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

With no annotations present, the description carries the burden and does well: it discloses that ID 0 is the Standard CONUS rate area, explains the meaning of the returned `name` vs `defined_name` fields, and scopes the response to metadata only. It omits error behavior for invalid IDs and any auth/rate-limit context, keeping it short of a 5.

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?

Front-loaded with the core purpose and organized into purpose, semantics, parameter meaning, and exclusions. Slightly verbose — the long docs URL and the name/defined_name aside add length without being essential to invoking the tool.

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?

No output schema exists, and the description compensates by describing the key returned fields (name, defined_name) and the geographic concept of a rate area. A brief note on the response envelope or behavior for unknown IDs would make it 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?

Schema coverage is 100% and already documents `destination_id` including the ID 0 convention, so much is duplication. However the description adds conceptual meaning beyond the schema by spelling out what a rate-area ID can represent geographically, which helps an agent reason about the value.

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 ('Get GSA destination metadata by ID') and immediately clarifies the semantic scope of a 'destination' (city, metro area, county, jurisdiction group, or Standard CONUS). This distinguishes it clearly from get_destinations (browse/list) and get_gsa_perdiem_by_destination (rates).

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?

Explicitly names alternatives and the conditions selecting them: use GET /v1/gsa/destinations to browse and obtain IDs, and use GET /v1/gsa/perdiem/destination/{destination_id} to get per diem rates for a date. It also states a negative constraint — this endpoint returns metadata only, not rates.

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