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

With no annotations, the description must disclose behavior. It mentions external API use (Open-Meteo) but fails to clarify that only the 'city' parameter is used, that other schema parameters are ignored, or that the call is read-only. The schema's many unrelated parameters create ambiguity that the description does not resolve.

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 concise sentence without fluff. However, it is so brief that it omits critical usage and behavioral context, though conciseness itself is appropriate.

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?

With nine parameters, no output schema, and no annotation, the description is insufficient. It does not explain the response format, what happens when non-city parameters are provided, or why those parameters exist. This is a significant gap for a tool that appears to have a shared schema.

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 each parameter has a description. The tool description adds no extra parameter meaning beyond the schema; thus the baseline of 3 applies.

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 retrieves current temperature for a city via Open-Meteo, specifying a verb, resource, and provider. It distinguishes from siblings like geo-hint or timezone, but does not explicitly contrast with other hint tools.

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, nor any mention of prerequisites or exclusions. The description only states what it does without context on selection criteria.

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