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

The description discloses the main side effect: showing the API key to the user and instructing them to configure it as a Bearer token. This is transparent about the output and subsequent user action. It does not mention error conditions or rate limits, but that is not critical for this verification action. No annotations are present, so the description carries the full transparency burden, which it mostly fulfills.

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 concise, consisting of two clear sentences. It states the action, the output, and the user instruction without any redundant wording or unnecessary detail. It is well-structured and front-loaded with the core purpose.

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 there is no output schema, the description explains what should be done with the returned key (show and instruct). It covers the essential context for an agent to complete the task. However, it does not mention potential failure scenarios (e.g., invalid code) or any additional context like token expiry, but for a simple verification step, this is adequate.

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 description provides no explanation of the 'email' and 'code' parameters beyond their names. The schema defines formats (email format and 6-digit pattern), but the description adds no semantic meaning, such as why the email is needed or how the code is validated. With 0% schema description coverage, the description fails to compensate for its lack of parameter guidance.

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 a 6-digit code for an API key and instructing the user to configure it. It uses specific verbs ('Exchange', 'Show', 'tell') and uniquely identifies the resource (account API key). This distinguishes it from sibling tools like create_account, which handles account creation.

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?

The description implies usage after receiving an emailed code, but it does not explicitly state when to use this tool versus alternatives such as create_account. No direct comparison or decision guidance is provided, leaving some ambiguity for an agent deciding between verification and other account-related operations.

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