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

With no annotations, the description carries the full burden of disclosure. It identifies a live data source but does not mention read-only behavior, caching, units, error handling, or the fact that the input schema allows many non-weather parameters that are discarded. It is not contradictory, but it is thin.

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 front-loaded sentence with no filler, making it easy to scan. It is concise to the point of being under-specified for a 9-parameter tool, but structurally it is well-formed.

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 9 optional parameters, 100% schema coverage, no output schema, and no annotations, the one-sentence description is insufficient. It does not explain return format (e.g., units), what happens when city is missing, which parameters to ignore, or how this relates to sibling hint tools.

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 applies: the input schema already documents every parameter. The description adds the Open-Meteo source and ties 'city' to temperature, but does not clarify which of the other eight optional parameters are relevant or how they interact; overall it neither exceeds nor badly fails the schema coverage baseline.

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 resource ('current temperature for a city') and names the data provider (Open-Meteo), which makes the tool's core function clear. It lacks an explicit verb like 'get' or 'fetch', but the noun phrase is unambiguous and differentiates it from sibling hint tools such as geo-hint.

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 about when to choose this tool over alternatives, no exclusions, and no indication that only the 'city' parameter should be supplied. The context implies weather lookups but never states the selection criteria.

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