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

Beyond the annotations, the description discloses the critical one-time return behavior and the side effect that already-in-flight deliveries will fail verification. This is exactly the behavioral context an agent needs before invoking a mutating secret-rotation 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 sentences, no filler, and the most important facts are front-loaded: a new secret is issued, it is returned once, and the operational risk is stated. Every word earns its place.

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?

For a single-parameter tool with no output schema, the description covers the essential behavior: what is issued, the one-time return, and the consequence of rotating during active deliveries. It does not specify the exact format of the returned secret, but 'return it ONCE' meaningfully describes the output.

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 input schema already documents binding_id as 'Id of the partner binding' with 100% coverage, so the description does not need to repeat it. It adds no extra meaning about the parameter, which is acceptable given the schema carries the definition.

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 names a specific action ('Issue'), a precise resource ('NEW HMAC signing secret'), and a target ('for a binding'). It also adds a distinguishing operational fact ('return it ONCE'), which separates it from generic update or create tools in the sibling list.

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 provides clear context on when to use this tool: rotate in a quiet window because in-flight deliveries signed with the previous secret will fail verification. It does not explicitly list exclusions or name an alternative tool, but the one-parameter operation makes the intended use unambiguous.

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