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

With no annotations, the description carries the behavioral disclosure burden. It names the external provider and indicates a read-only current-temperature lookup, which is useful context. It does not mention units, error behavior, response format, or side effects, creating some ambiguity.

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, clear, front-loaded sentence with no filler. It quickly conveys the core function and data source, which is appropriately concise for the tool's apparent simplicity.

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 description is enough to select and invoke the tool with a city name, but because there is no output schema and no annotations, it leaves important context unspecified, such as the temperature unit, response format, and error behavior. It is adequate but has clear gaps.

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 the parameters and their discard behaviors. The tool description adds no new parameter semantics beyond implying that 'city' is the relevant input for a weather lookup.

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 conveys that the tool returns the current temperature for a city and identifies the external source, Open-Meteo. It lacks an explicit verb and does not explicitly differentiate it from siblings, but the weather-specific resource makes its purpose evident.

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 implies usage when a current city temperature is needed and that Open-Meteo is a public data source. However, it does not state when not to use the tool, provide exclusion conditions, or mention any alternative tools, leaving the guidance to inference.

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