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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It does not state whether the operation is read-only, what it returns (temperature units, format), whether there are side effects, or how it handles the many parameters that are not city-related. The description is silent on behavior beyond the basic claim.

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, which is concise and front-loaded with the core purpose. However, it is under-specified; it does not explain the role of the many parameters or the output. It is concise but not informative, so it does not earn its place beyond a basic statement.

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 parameters, none required, and no output schema. The description covers only the city-temperature use case and ignores the other parameters, which are all described in the schema as 'discarded' or 'checked'. It does not explain the tool's overall behavior or how the parameters interact, leaving the agent guessing. This is a significant gap for a multi-parameter tool.

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%, but the parameter descriptions are generic and unrelated to the weather purpose (e.g., 'ref' is a Git ref, 'url' is a URL). The description adds no meaning to parameters; it only implies 'city' is relevant. The schema's descriptions do not clarify how to use them for this tool, so the description fails to compensate.

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 verb ('Current temperature'), a resource ('temperature for a city'), and a source ('via Open-Meteo'). It is clear about the primary function, though it does not differentiate from siblings like 'geo-hint' or 'lib-docs-hint'. The narrow scope conflicts with the broad schema, creating ambiguity about the tool's actual purpose.

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 offers no guidance on when to use this tool versus alternatives. It does not mention exclusions, prerequisites, or scenarios where a different sibling (e.g., 'geo-hint') would be more appropriate. The single sentence leaves the agent to infer usage from the schema, which is insufficient.

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