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

Annotations flag this as a non-idempotent write, and the description adds genuinely useful behavior beyond them: the key is shown exactly once and only a hash is retained, and it is used via an 'Authorization: Bearer <key>' header. It does not spell out that repeated calls mint additional distinct keys, which is the main remaining gap for a non-idempotent operation.

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?

Two tight sentences with zero filler; the core action leads and the crediting/rate-limit benefit and key-handling caveat follow immediately.

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?

With no output schema, the description usefully discloses the one thing an agent must know about the response — that the returned key is unrecoverable. It stops short of describing success/error shape or the exact response field, but what it covers is the critical part.

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?

Schema description coverage is 100%, so both parameters (handle, email) are already documented in the schema, establishing the baseline of 3. The description contextualizes the handle as public and tied to crediting, but adds no format or constraint detail beyond the 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?

States a specific verb and resource ('Creates an Agents Handbook contributor key') plus the reason it exists (crediting and higher rate limits). This clearly separates it from siblings like report_run and submit_playbook, which consume such a key rather than create one.

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 gives a clear trigger context: register so that run reports and submissions are credited and rate-limited more generously. It does not name alternatives or explicitly say when not to use it, but the prerequisite role relative to the reporting/submission tools is inferable.

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