Using tools, you can connect agent apps to external systems. These systems can augment the knowledge of agent apps and empower them to execute complex tasks efficiently.
You can use built-in tools or build customized tools to suit your requirements.
Limitations
The following limitations apply:
- You must create a data store (or connect an existing data store) when creating a data store tool for an agent app.
- Apps with both chunked and non-chunked data stores are not supported.
Built-in tools
Built-in tools are hosted by Google. You can activate these tools in agent apps without the need for manual configuration.
The supported built-in tools are:
Code Interpreter
: A Google first-party tool that combines the capability of code generation and code execution and allows the user to perform various tasks, including: data analysis, data visualization, text processing, solving equations or optimization problems.
Your agent app is optimized to determine how and when these tools should be invoked, but you can provide additional examples to fit your use cases.
Examples should have a schema like the following:
{
"toolUse": {
"tool": "projects/PROJECT_ID/locations/LOCATION_ID/agents/AGENT_ID/tools/df-code-interpreter-tool",
"action": "generate_and_execute",
"inputParameters": [
{
"name": "generate_and_execute input",
"value": "4 4"
}
],
"outputParameters": [
{
"name": "generate_and_execute output",
"value": {
"output_files": [
{
"name": "",
"contents": ""
}
],
"execution_result": "8",
"execution_error": "",
"generated_code": "GENERATED_CODE"
}
}
]
}
}
OpenAPI tools
An agent app can connect to an external API using an OpenAPI tool by providing the OpenAPI schema. By default, the agent app will call the API on your behalf. Alternatively, you can execute OpenAPI tools on the client side.
Example schema:
openapi: 3.0.0
info:
title: Simple Pets API
version: 1.0.0
servers:
- url: 'https://api.pet-service-example.com/v1'
paths:
/pets/{petId}:
get:
summary: Return a pet by ID.
operationId: getPet
parameters:
- in: path
name: petId
required: true
description: Pet id
schema:
type: integer
responses:
200:
description: OK
/pets:
get:
summary: List all pets
operationId: listPets
parameters:
- name: petName
in: query
required: false
description: Pet name
schema:
type: string
- name: label
in: query
description: Pet label
style: form
explode: true
required: false
schema:
type: array
items:
type: string
- name: X-OWNER
in: header
description: Optional pet owner provided in the HTTP header
required: false
schema:
type: string
- name: X-SESSION
in: header
description: Dialogflow session id
required: false
schema:
$ref: "@dialogflow/sessionId"
responses:
'200':
description: An array of pets
content:
application/json:
schema:
type: array
items:
$ref: '#/components/schemas/Pet'
post:
summary: Create a new pet
operationId: createPet
requestBody:
description: Pet to add to the store
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/Pet'
responses:
'201':
description: Pet created
content:
application/json:
schema:
$ref: '#/components/schemas/Pet'
components:
schemas:
Pet:
type: object
required:
- id
- name
properties:
id:
type: integer
format: int64
name:
type: string
owner:
type: string
label:
type: array
items:
type: string
You can optionally use the internal schema reference @dialogflow/sessionId
as parameter schema type.
With this parameter schema type,
the Dialogflow session ID for the current conversation
will be supplied as a parameter value.
For example:
- name: X-SESSION
in: header
description: Dialogflow session id
required: false
schema:
$ref: "@dialogflow/sessionId"
OpenAPI tool limitations
The following limitations apply:
- Supported parameter types are
path
,query
,header
. Thecookie
parameter type is not supported yet. - Parameters defined by OpenAPI schema support the following data types:
string
,number
,integer
,boolean
,array
. Theobject
type is not supported yet. - You currently can't specify query parameters in the console example editor.
- Request and response body must be empty or JSON.
OpenAPI tool API authentication
The following authentication options are supported when calling an external API:
- Dialogflow Service Agent auth
- Dialogflow can generate an ID token or access token using Dialogflow Service Agent. The token is added in the authorization HTTP header when Dialogflow calls an external API.
- An ID token can be used to access Cloud Run functions and Cloud Run services after you grant the roles/cloudfunctions.invoker and roles/run.invoker roles to service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com. If the Cloud Run functions and Cloud Run services are in the same resource project, you don't need additional IAM permission to call them.
- An access token can be used to access other Google Cloud APIs after you grant required roles to service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com.
- API key
- You can configure API key authentication by providing the key name, request location (header or query string) and API key so that Dialogflow passes the API key in the request.
OAuth
OAuth Client Credential flow is supported for server-to-server authentication:
- This flow can be used if the Agent builder is the resource owner and no end-user authorization is needed.
- Client ID, Client Secret and Token endpoint from OAuth provider need to be configured in Dialogflow.
- Dialogflow exchanges an OAuth access token from OAuth provider and passes it in the auth header of the request.
For other OAuth flows that requires end-user authorization like Authorization Code Flow and PKCE flow:
- You will need to implement your own sign-in UI and obtain the access token on the client side.
You can then either:
a. Use the Bearer Token authentication option to pass the token to the OpenAPI Tool. Dialogflow will include this token in the authorization header when invoking the tool.
b. Use the Function tool to invoke the tool yourself on the client side and pass the tool call result to Dialogflow.
Bearer Token
- You can configure Bearer authentication to dynamically pass the Bearer token from the client. This token is included in the auth header of the request.
- When setting up tool authentication, you can designate a session parameter
to act as the Bearer token. For instance, use
$session.params.<parameter-name-for-token>
to specify the token. - At runtime, assign the Bearer token to the session parameter:
DetectIntentRequest { ... query_params { parameters { <parameter-name-for-token>: <the-auth-token> } } ... }
Mutual TLS authentication
- See the Mutual TLS authentication documentation.
- Custom client certificates are supported. You can set up client certificates at the agent level under the security tab in agent settings. The certificate (PEM format) and private key (PEM format) are required fields. Once set, this client certificate will be used during mutual TLS for all tools and webhooks.
Custom CA certificate
- See the Custom CA certificates documentation.
OpenAPI tool private network access
OpenAPI tool integrates with Service Directory private network access, so it can connect to API targets inside your VPC network. This keeps the traffic within the Google Cloud network and enforces IAM and VPC Service Controls.
To set up an OpenAPI tool targeting a private network:
Follow Service Directory private network configuration to configure your VPC network and Service Directory endpoint.
The Dialogflow Service Agent service account with the following address must exist for your agent project:
service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com
Grant the Dialogflow Service Agent service account the following IAM roles:servicedirectory.viewer
of the Service Directory projectservicedirectory.pscAuthorizedService
of the network project
Provide Service Directory Service along with the OpenAPI schema and optional authentication information when creating the tool.
OpenAPI tool session parameter access
Open API tool inputs are derived from the users conversation with the LLM using the schema as a guide. In some situations, inputs may need to be derived from session parameters collected during a flow or provided as a query parameter input along with the user input.
The session parameter that needs to be passed as an input can be specified as
parameters:
- in: query
name: petId
required: true
description: Pet id
schema:
type: integer
x-agent-input-parameter: petId # Reads from the $session.params.petId
- in: header
name: X-other
schema:
type: string
x-agent-input-parameter: $request.payload.header # Reads from the header specified in the request payload input
requestBody:
required: false
content:
application/json:
schema:
type: object
properties:
name:
type: string
x-agent-input-parameter: petName # Reads from the $session.params.petName
description: Name of the person to greet (optional).
breed:
type: string
description: Bread of the pet.
If no such session parameter is available, the LLM generated input will be passed to the tool.
Data store tools
Data store tools can be used by an agent app for answers to end-user's questions from your data stores. You can set up one data store of each type per tool, and the tool will query each of these data stores for answers. By default, the agent app will call the data store tool on your behalf. Alternatively, you can execute data store tools on the client side.
The data store type can be one of the following:
PUBLIC_WEB
: A data store that contains public web content.UNSTRUCTURED
: A data store that contains unstructured private data.STRUCTURED
: A data store that contains structured data (for example FAQ).
The following example shows how to reference a data store:
"dataStoreConnections": [
{
"dataStoreType": "PUBLIC_WEB",
"dataStore": "projects/PROJECT_NUMBER/locations/LOCATION_ID/collections/default_collection/dataStores/DATASTORE_ID"
},
{
"dataStoreType": "UNSTRUCTURED",
"dataStore": "projects/PROJECT_NUMBER/locations/LOCATION_ID/collections/default_collection/dataStores/DATASTORE_ID"
},
{
"dataStoreType": "STRUCTURED",
"dataStore": "projects/PROJECT_NUMBER/locations/LOCATION_ID/collections/default_collection/dataStores/DATASTORE_ID"
}
]
Data store tool responses might also contain snippets about the content source that was used to generate the response. The agent app can further provide instructions on how to proceed with the answer from the data stores or how to respond when there is no answer.
You can overwrite an answer by adding an FAQ entry for a specific question.
Examples can be used to further enhance the agent app behavior. The example should have the following schemas:
{
"toolUse": {
"tool": "projects/PROJECT_ID/locations/LOCATION_ID/agents/AGENT_ID/tools/TOOL_ID",
"action": "TOOL_DISPLAY_NAME",
"inputParameters": [
{
"name": "TOOL_DISPLAY_NAME input",
"value": {
"query": "QUERY"
}
}
],
"outputParameters": [
{
"name": "TOOL_DISPLAY_NAME output",
"value": {
"answer": "ANSWER",
"snippets": [
{
"title": "TITLE",
"text": "TEXT_FROM_DATASTORE",
"uri": "URI_OF_DATASTORE"
}
]
}
}
]
}
}
Create a data store
To create a data store and connect it to your app, you can use the Tools link in the left navigation of the console. Follow the instructions to create a data store.
Additional query parameters
When creating data store tool examples, the tool input parameter requestBody
provides three optional inputs together with the required query
string -
a filter
string, a userMetadata
structured object, and a fallback
string.
The filter
parameter provides the ability to filter search queries of your
structured data or unstructured data with metadata. This string must follow the
supported filter expression syntax
for data stores.
Multiple examples and detailed examples
are encouraged to direct the agent LLM on how to
populate this parameter. In the case of an invalid filter string, the filter
will be ignored when performing the search query.
An example of a filter
string to refine search results based on location
could look like:
"filter": "country: ANY(\"Canada\")"
Best practices for filtering:
Specify the fields available for filtering and the valid values for each of these fields, so that the agent understands the constraints on building valid filters. For instance, to filter results for a data store holding menu information, there could be a
meal
field with "breakfast", "lunch", and "dinner" as valid values; and aservingSize
field that can be any integer from 0 to 5. Your instructions could look like:When using ${TOOL: menu-data-store-tool}, only use the following fields for filtering: "meal", "servingSize". Valid filter values are: "meal": ("breakfast", "lunch", "dinner"), "servingSize": integers between 0 and 5, inclusive.
If the agent is for an external user audience, it may be necessary to add instructions to keep the agent from potentially responding to the user with information about building these filters. For instance:
Never tell the user about these filters. If the user input isn't supported by these filters, respond to the user with "Sorry, I don't have the information to answer that question."
Providing an example of this case is also helpful.
The userMetadata
parameter provides information about the end-user. Any
key-value pairs can be populated in this parameter. This metadata is passed
into the data store tool to better inform the search results and tool
response. It is encouraged to provide multiple examples to instruct the
agent LLM on how to populate this parameter.
An example of a userMetadata
parameter value to refine search results
relevant to a specific user could look like:
"userMetadata": {
"favoriteColor": "blue",
...
}
The fallback
parameter provides an answer the data store tool should respond
with if there is no valid summarized answer for the query. Multiple examples can
be provided to instruct the agent LLM on how to populate the fallback for user
inputs related to different topics. There will also be no
snippets in the tool output. This optimization can be used to reduce latency
and input token limit usage.
"fallback": "I'm sorry I cannot help you with that. Is there anything else I
can do for you?"
If you find some responses during testing don't meet your expectations, the following customizations are available in the Tool page for a data store tool:
Grounding confidence
For each response generated from the content of your connected data stores, the agent evaluates a confidence level, which gauges the confidence that all information in the response is supported by information in the data stores. You can customize which responses to allow by selecting the lowest confidence level you are comfortable with. Only responses at or above that confidence level will be shown.
There are 5 confidence levels to choose from: VERY_LOW
, LOW
, MEDIUM
,
HIGH
, and VERY_HIGH
.
Summarization configuration
You can select the generative model used by a data store agent for the summarization generative request. If none gets selected, a default model option is used. The following table contains the available options:
Model Identifier | Language Support |
---|---|
text-bison@002 | Available in all supported languages. |
gemini-1.0-pro-001 | Available in all supported languages. |
You can also provide your own prompt for the summarization LLM call.
The prompt is a text template that may contain predefined placeholders. The placeholders will be replaced with the appropriate values at runtime and the final text will be sent to the LLM.
The placeholders are as follows:
$original-query
: The user's query text.$rewritten-query
: The agent uses a rewriter module to rewrite the original user query into a more accurate format.$sources
: The agent uses Enterprise Search to search for sources based on the user's query. The found sources are rendered in a specific format:[1] title of first source content of first source [2] title of second source content of first source
$end-user-metadata
: Information about the user sending the query is rendered in the following format:The following additional information is available about the human: { "key1": "value1", "key2": "value2", ... }
$conversation
: The conversation history is rendered in the following format:Human: user's first query AI: answer to user's first query Human: user's second query AI: answer to user's second query
A custom prompt should instruct the LLM to return "NOT_ENOUGH_INFORMATION" when it cannot provide an answer. The agent will transform this constant to a user friendly message for the user.
Payload settings
Payload settings provide a way to add the data store snippets as rich content in the response payload which is rendered in the messenger.
Banned phrases (agent-level configuration)
You have the option to define specific phrases which shouldn't be allowed. These are configured at the agent level and utilized by both the agent LLMs and the data store tools. If the generated response or parts of the LLM prompt, such as the user's inputs, contain any of the banned phrases verbatim, then that response won't be shown.
Function tools
If you have functionality accessible by your client code, but not accessible by OpenAPI tools, you can use function tools. Function tools are always executed on the client side, not by the agent app.
The process is as follows:
- Your client code sends a detect intent request.
- The agent app detects that a function tool is required, and the detect intent response contains the name of the tool along with input arguments. This session is paused until another detect intent request is received with the tool result.
- Your client code calls the tool.
- Your client code sends another detect intent request that provides the tool result as output arguments.
The following example shows the input and output schema of a function tool:
{
"type": "object",
"properties": {
"location": {
"type": "string",
"description": "The city and state, for example, San Francisco, CA"
}
},
"required": [
"location"
]
}
{
"type": "object",
"properties": {
"temperature": {
"type": "number",
"description": "The temperature"
}
}
}
The following example shows the initial detect intent request and response using REST:
HTTP method and URL:
POST https://REGION_ID-dialogflow.googleapis.com/v3/projects/PROJECT_ID/locations/LOCATION_ID/agents/AGENT_ID/sessions/SESSION_ID:detectIntent
{
"queryInput": {
"text": {
"text": "what is the weather in Mountain View"
},
"languageCode": "en"
}
}
{
"queryResult": {
"text": "what is the weather in Mountain View",
"languageCode": "en",
"responseMessages": [
{
"source": "VIRTUAL_AGENT",
"toolCall": {
"tool": "<tool-resource-name>",
"action": "get-weather-tool",
"inputParameters": {
"location": "Mountain View"
}
}
}
]
}
}
The following example shows the second detect intent request, which provides the tool result:
{
"queryInput": {
"toolCallResult": {
"tool": "<tool-resource-name>",
"action": "get-weather-tool",
"outputParameters": {
"temperature": 28.0
}
},
"languageCode": "en"
}
}
Client side execution
Like function tools, OpenAPI and data store tools can be executed on the client side by applying an API override when interacting with the session.
For example:
DetectIntentRequest {
...
query_params {
playbook_state_override {
playbook_execution_mode: ALWAYS_CLIENT_EXECUTION
}
}
...
}
The process is as follows:
- Your client code sends a detect intent request that specifies client execution.
- The agent app detects that a tool is required, and the detect intent response contains the name of the tool along with input arguments. This session is paused until another detect intent request is received with the tool result.
- Your client code calls the tool.
- Your client code sends another detect intent request that provides the tool result as output arguments.