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

The description adds behavioral context beyond annotations by explaining that a 'pending' result means the user hasn't approved, and a 'complete' result yields a private sessionToken. It also warns to never expose the secrets, adding security-relevant behavior.

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 three concise sentences, front-loaded with the action, and includes a necessary security warning. Every sentence earns its place without redundancy.

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?

Given no output schema, the description covers the main outcomes (pending/complete) and the returned sessionToken, which is adequate for a sign-in completion tool. It doesn't discuss error cases, but the core context is sufficiently complete.

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?

With 0% schema description coverage, the description compensates by identifying both parameters (requestId, pollSecret) and indicating they are private secrets exchanged in the process. It doesn't detail each parameter individually but adds meaning beyond the bare schema.

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 the tool's function: exchanging private requestId and pollSecret to complete a sign-in. It specifies the resources involved and the action, distinguishing it from sibling tools like begin_sign_in.

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 tool should be used 'after browser approval' and explains the pending vs. complete outcomes, guiding when to call. It doesn't explicitly name alternatives, but the sign-in flow context makes the usage clear.

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