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

Annotations are absent, so the description bears the full burden of behavioral disclosure. The one-line description reveals only that it fetches temperature via Open-Meteo, but says nothing about how inputs are handled, whether network calls are made, what happens with the nine schema parameters, or any side effects. The schema hints at discarding inputs, but the description itself provides minimal behavioral context.

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. It is efficient and to the point. However, given the tool's complexity (9 parameters, none required), the brevity borders on under-specification, though it is still concise rather than verbose.

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, many seemingly unrelated to weather (ref, url, feed, host, json, path, zone, query), and no output schema or annotations. The description covers only the city parameter and the weather purpose, offering no explanation for the other inputs or the return format. This is severely incomplete for an agent to call correctly.

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 every parameter. The description adds only the context that the tool is about weather, which is not evident from parameter names alone. It does not elaborate on how parameters like ref, url, or feed relate to the weather function, leaving ambiguity. This meets the baseline but adds little beyond the schema.

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 a specific action: getting the current temperature for a city via Open-Meteo. It names the resource (city) and the provider, and the tool name 'weather-hint' reinforces this. However, it does not explicitly differentiate from sibling tools like geo-hint or lib-docs-hint, though the weather focus is implicit.

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 on when to use this tool versus the 27 siblings. The description only states what it does, not when it is the appropriate choice or what conditions select it. There is no mention of alternatives or exclusions, leaving the agent to guess.

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