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

With no annotations, the description carries the full burden. It only says it retrieves temperature via Open-Meteo, but does not disclose that the tool appears to handle other hint types (based on schema), whether it makes external network calls, or what the response format is. The description contradicts the schema's hint of multi-purpose behavior.

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 a single short sentence with no fluff, which is concise, but it omits essential context and is not adequately structured to convey the tool's actual complexity. It is under-specified rather than efficiently complete.

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 the tool has 9 parameters, no required fields, no output schema, and no annotations, the description is severely inadequate. It does not explain the different hint modes, the external dependency on Open-Meteo, or how to choose parameters. An agent cannot reliably use this tool based on the current description.

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%, so each parameter has a description, but the tool description only mentions 'city' and does not explain the role of the other eight parameters. The descriptions in the schema suggest each is used for a different kind of hint, yet the tool description implies a weather-only function, leaving agents confused about which parameter to use for what.

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 function ('Current temperature for a city via Open-Meteo'), but the input schema contains nine parameters, most of which are unrelated to weather (e.g., 'url', 'json', 'path', 'zone'). This makes the actual scope ambiguous and does not distinguish it from sibling tools like 'geo-hint' or 'browser-url-ok'.

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?

No guidance is given on when to use this tool versus alternatives. There is no mention of the multiple parameter-specific behaviors implied by the schema (e.g., shape checks, normalization), nor any exclusions or conditions for weather lookups.

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