Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description describes a state-changing operation ('exchange', 'claim'), which contradicts the readOnlyHint=true annotation. Claiming a one-time token inherently consumes it, so the annotation is misleading. This is an annotation contradiction, warranting a score of 1.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence that immediately conveys the action, condition, and inputs without wasted words. Every phrase contributes meaning.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description provides the essential steps and outcome, and an output schema exists to explain return values. However, it could have mentioned that the claim token is consumed (which would also flag the contradiction) and any failure modes, but given the output schema, this is not a major gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema covers all 8 parameters with descriptions, but the description adds value by explicitly identifying purchase_id and claim_token as the key exchange inputs and mentioning the resulting key usage ('X-Toofi-Agent-Key or agent_key'). This goes beyond the schema's 'returned by create_agent_checkout_session' notes.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states a specific action ('exchange the purchase id and one-time claim token for the Toofi agent API key') with a clear resource (the API key) and precondition (after Stripe Checkout is paid). This distinguishes it from sibling tools like create_agent_checkout_session, which creates the session that this tool claims.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly states the timing ('After Stripe Checkout is paid') and the required inputs (purchase id and claim token), which implies this is used as the second step after create_agent_checkout_session. It does not explicitly mention alternatives or when not to use it, but the context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.