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

Annotations already establish the read-only, idempotent, open-world, non-destructive safety profile. The description adds substantial operational context beyond annotations: upstream data source (ll.thespacedevs.com), no auth requirement, a 15-request/hour throttle shared across agents, and 24-hour caching. This helps an agent anticipate rate limiting and data freshness.

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 two sentences, front-loading the core function and return fields before moving to operational notes. Every clause adds value — the first sentence covers purpose and output, the second covers data source, auth, throttling, and caching.

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 only 2 optional parameters, an output schema present, and annotations covering safety, the description supplies all necessary invocation context: what is searched, what is returned, data origin, auth requirements, throttling, and caching. No critical gaps exist for an agent deciding whether and how to call it.

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 coverage is 100%: both 'limit' and 'search' have full descriptions with constraints and examples. The description's mention of 'optionally filtered by a free-text search' adds little beyond the schema's existing 'search' field description. With the schema carrying the parameter semantics, baseline 3 is appropriate.

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 states a specific verb ('Search'), a precise resource ('the global astronaut roster'), and enumerates the returned fields (name, active/retired status, sponsoring agency). It clearly distinguishes itself from the agency and launch siblings and is not a tautology.

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 use for astronaut roster queries and mentions optional free-text filtering, but it never explicitly states when to choose this tool over alternatives like launch-library-2.agencies.search or the launches tools. There are no exclusionary or alternative-routing statements, so guidance is only implicit.

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