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

With no annotations, the description bears the full burden of behavioral disclosure. It only mentions 'via Open-Meteo' which hints at a network call, but does not explain that most parameters are ignored, what the output looks like, or any side effects. The parameter descriptions in the schema say fields are 'discarded after the call,' but the main description omits this, leaving the agent to infer unexpected behavior.

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 short sentence, which is concise and front-loaded with the main purpose. However, it is so minimal that it sacrifices informativeness; it does not earn its place by providing enough detail to guide correct usage. It is under-specified rather than optimally concise.

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?

For a tool with nine parameters, no output schema, and no annotations, the description is severely incomplete. It does not explain the role of the non-city parameters, what the return value contains, or how the tool relates to its siblings. An agent cannot confidently call this tool correctly based on the description alone.

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 parameter-specific information beyond what the schema already provides. The schema clarifies that only 'city' is relevant, but the description does not emphasize this, so the baseline of 3 is appropriate.

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 returns the current temperature for a city via Open-Meteo, giving a specific verb and resource. However, it does not differentiate from sibling tools like geo-hint or timezone, and the presence of nine unrelated parameters in the schema creates ambiguity about the tool's actual scope.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention prerequisites, conditions, or scenarios where weather-hint is preferred over sibling tools. It simply states the core function without any contextual direction.

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