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

With no annotations, the description must disclose behavior itself; it only says the data comes from Open-Meteo. It does not mention that this is an external read-only call, that only the city parameter is used, or that the other eight parameters are discarded, which is critical behavioral context given the schema.

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 one short sentence with no filler and front-loads the core purpose. It sacrifices detail, but for the tiny amount of information it does convey, the structure is efficient.

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 tool with nine parameters, no annotations, and no output schema, the description is incomplete. It does not explain the irrelevant/discarded parameters, the response shape, or the external dependency beyond naming Open-Meteo.

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 the baseline is 3. The description adds no parameter meaning beyond the schema; it only aligns with the city field and does not clarify why url, feed, host, json, path, zone, query, and ref exist.

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 the tool returns the current temperature for a city and identifies the data source, Open-Meteo, which is more specific than a vague 'weather tool'. However, it lacks a verb and does not explicitly distinguish this from siblings like geo-hint.

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 phrase 'Current temperature for a city' implies the use case: when an agent needs current city temperature. It does not mention alternatives or exclusions, so there is no explicit guidance on when to prefer this over sibling hint tools.

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