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

With no annotations, the description must disclose behavioral traits itself. It only mentions the temperature retrieval but says nothing about how the other eight parameters are handled (e.g., that they are discarded or ignored). The schema descriptions hint at this, but the tool description does not convey the actual behavior, such as side effects or read-only nature.

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 with zero filler. It front-loads the core purpose. For a tool with such a narrow focus, this is appropriately terse, though it sacrifices completeness.

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 output schema, and no annotations, a one-sentence description is insufficient. The agent has no idea how to use the non-weather parameters, what the response format is, or when to prefer this over a sibling. This is a significant completeness gap.

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 additional meaning beyond the schema; it only mentions 'city' while ignoring the other parameters, some of which are clearly unrelated to weather (ref, url, json, etc.). It does not clarify why those parameters exist or how they interact with the weather query.

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 clear verb ('current temperature') and a resource ('a city via Open-Meteo'), so an agent can infer the primary function. However, it does not differentiate from siblings like geo-hint or timezone, which might also serve location-based queries, so it lacks explicit sibling contrast.

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 no guidance on when to use this tool versus alternatives. It doesn't mention exclusions, prerequisites, or situations where another tool would be more appropriate, leaving the agent to guess.

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