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

With no annotations, the description must carry behavioral disclosure. It reveals an external call to Open-Meteo but does not explicitly state that the operation is read-only/stateless, how unknown cities are handled, or what the returned temperature looks like (e.g., numeric value, units).

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 sentence with no filler and is front-loaded with the key action. It is concise, though slightly under-specified for the tool's actual schema breadth.

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?

The tool has 9 optional parameters, no annotations, and no output schema, but the description only addresses city weather. It does not explain the purposes of the other eight parameters, whether they are supported, or how to interpret the absence of required parameters, making the definition incomplete for safe invocation.

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 schema already documents all parameters, including 'city' and the discarded behavior. The description names 'city' but adds no parameter meaning beyond the schema, so 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 that the tool returns the current temperature for a city via Open-Meteo, giving a specific resource and data source. It distinguishes weather-hint from sibling time/geo/validation tools, though it lacks an explicit verb like 'returns'.

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?

Usage is implied: if a user asks for the current temperature of a city, this is the tool. However, it does not explicitly say when to prefer it over alternatives or note that only the 'city' parameter is relevant, and the broad schema with 9 optional parameters leaves correct invocation ambiguous.

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