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

Annotations already cover readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, so the description does not need to restate safety. It adds licensing (CC BY 4.0) and no-auth requirements, which are useful but not operational behavior. It does list the returned fields, which gives some insight into the response, but does not describe any special behavior like caching, error handling, or rate limits. With annotations present, this is adequate but not extensive.

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-loaded with the core action and returned fields, followed by the input source and licensing. Every sentence contributes essential information without redundancy. It is concise and well-structured for quick comprehension.

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 read-only lookup with an existing output schema and annotations covering safety, the description is fully complete. It states purpose, input source, returned fields, and data provenance. No critical information is missing that would prevent an agent from invoking the tool correctly.

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 the schema already describes station_id with an example. The description adds value by explicitly stating the provenance (from meteostat.stations_nearby), which helps the agent understand where to obtain the ID. This goes beyond the schema's static description and provides actionable guidance, hence above the baseline of 3.

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 a specific verb (Get), resource (metadata for a weather station), and the exact identifier (by ID). It enumerates the returned fields (name, country/region, coordinates, timezone, date ranges), which distinguishes it from sibling tools like observations or nearby stations. The purpose is unambiguous and distinguishable from meteostat.observations.* and meteostat.stations.nearby.

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 by stating that the station ID comes from meteostat.stations_nearby, which directly guides the agent on how to obtain the required input. It does not explicitly state when not to use it or name alternative tools, but the context is sufficient for typical invocation. The adjacency to observation tools implies it's for metadata lookup, not data retrieval, but that is not explicit.

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