AddThisFeature

AI Tool Calling Framework

Give the model a governed catalogue of app actions instead of ad hoc, unchecked calls.

involved AI Assistants

What it adds

A registry of app capabilities exposed to the model, with per-user scoping, strict argument validation, execution limits, and an audit trail.

What your agent is told to do

5
  1. 1

    Define each tool once in a registry with its purpose, its argument schema, the permission it requires, and whether it reads or writes. Anything not in the registry is not callable.

  2. 2

    Build the tool list per request from the current user, workspace, and context. Do not publish the full catalogue and rely on the model to avoid the tools it should not use.

  3. 3

    Validate every argument against the schema and reject the call on any deviation. Then apply the same authorization checks the ordinary interface applies, in the app's own code, because a tool call is an untrusted request that happens to arrive from a model.

  4. 4

    Enforce ceilings on the number of calls per turn, recursion depth, wall-clock time, and token or cost spend. Stop cleanly at the ceiling with an explanation rather than looping until something times out.

  5. 5

    Do not let a write tool execute directly when a user-visible plan is warranted. Approval, plan display, and partial-failure reporting are owned by AI Agent Actions with Approval; this framework owns the catalogue, validation, and limits it runs on.

Edge cases it handles

8
  • The tool list is scoped per request. A user who loses access mid-conversation must not be able to call a tool that was available earlier in the same thread.
  • Reject any call whose arguments fail the schema, including extra fields, wrong types, or out-of-range values, and return the rejection to the model as a correctable error rather than coercing the value into something plausible.
  • Tool results are untrusted input. Text pulled from a record, a document, or a third party may contain instructions aimed at the model, so it must be clearly delimited as data and must never be able to grant permissions or expand the tool list.
  • Ceilings on call count, recursion, execution time, and spend must all be enforced, and the loop must terminate visibly at whichever is hit first. A model that calls the same read tool repeatedly is the normal failure, not the rare one.
  • Record every call, its arguments, its outcome, and its duration, with secrets, tokens, and personal data redacted before anything is written. The log exists to explain what happened, not to reproduce the payload.
  • A tool that fails, times out, or is unavailable must return a structured failure the model can reason about, rather than an exception that ends the conversation.
  • Write tools need idempotency keys, because a model that does not see a result will call again.
  • Registry changes are a compatibility surface. Removing or renaming a tool must not break conversations already in flight.

Definition of done

9
  • Only registered tools are callable, and the list offered is built per request from the current user and context.
  • Every argument is validated against a strict schema, and failing calls are rejected rather than coerced.
  • Authorization is enforced in application code on every call, independently of the tool list.
  • Call count, recursion depth, execution time, and spend ceilings are enforced and terminate the loop cleanly.
  • Tool output is treated as untrusted data and cannot expand the model's permissions or tool list.
  • Every call and outcome is recorded with secrets and personal data redacted.
  • Tool failures return a structured result rather than ending the conversation.
  • The feature matches the existing design system.
  • No existing functionality is broken.

Related features

How it works

  1. 1

    Copy the link

    Grab the Markdown instruction URL for this feature.

  2. 2

    Give it to your AI

    Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.

  3. 3

    It inspects, then implements

    Your agent reads your existing app first, then adds the feature to fit it.

Works with your stack

These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.

Need it tighter than that? Customize the feature and tell it exactly what you're running.