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

With no annotations, the description carries the full burden of explaining behavior. It only says the source is Open-Meteo and that the result is a current temperature; it omits that the other schema parameters are shape-check values to be discarded, what the tool actually returns for invalid inputs, and any network/rate-limit implications of calling an external weather API.

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 excess fluff. It is far too short to carry the full meaning of a 9-parameter, no-annotation tool, so while it is concise, it is not appropriately sized for the tool's complexity.

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 tool has 9 optional parameters, no output schema, no annotations, and no mention of what happens when the relevant parameter is absent, a single sentence is not enough. An agent cannot confidently know the return shape or how to use the tool correctly beyond guessing by the 'city' key.

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 what each parameter means and that most are discarded after checks. The description adds no parameter-specific meaning beyond mentioning 'a city', but the schema itself does the heavy lifting, warranting the baseline of 3.

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 names a specific deliverable ('current temperature') and the datasource ('Open-Meteo'), so an agent can infer this tool is about weather lookups. It does not explicitly contrast itself with similar siblings like geo-hint, but the weather-specific wording is enough to separate it from the general hint/shape tools.

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 a use case ('current temperature for a city') but gives no guidance on when to choose this over sibling tools, nor does it mention that many schema parameters are discarded. It provides no explicit trigger conditions, exclusions, or alternatives.

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