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

With no annotations provided, the description carries the full burden of disclosing behavior. It only mentions retrieving a temperature via Open-Meteo and says nothing about how the other eight parameters are handled (e.g., they are discarded after checks, per their schema descriptions). It does not explain that the tool performs validations or shape checks, nor does it mention any rate limits, response format, or side effects. The agent is left without essential 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 extremely short (one sentence), which might be considered concise, but it is under-specified rather than efficient. It lacks structure such as separating the primary use case from the general hint mechanism. The brevity leads to major gaps rather than clear communication, so it does not earn credit for conciseness.

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's complexity—9 optional parameters, no output schema, and no annotations—the description is grossly incomplete. It fails to mention the tool's role as a hint provider that validates or returns a simple value based on input type. An agent would not understand how to handle non-city parameters or what the return value looks like for those cases. The description covers only a fraction of the tool's behavior.

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 coverage is 100%, so the schema documents all parameters, but the description adds no value by only referencing 'city' while leaving seven parameters unexplained. It fails to clarify that many parameters are ignored or discarded based on the type of hint requested, and it does not help the agent decide which parameter to supply for a weather query. The description's minimal mention of city does not compensate for the silent handling of the rest.

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 'Current temperature for a city via Open-Meteo,' which is specific for a weather lookup, but the input schema includes eight other optional parameters (ref, url, feed, host, json, path, zone, query) that are not mentioned at all. This creates significant ambiguity about the tool's actual scope; the tool appears to be a generic hint/validation tool that happens to return temperature for cities, making the stated purpose only partially accurate and misleading.

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. Sibling tools like geo-hint or timezone clearly overlap in purpose, yet the description offers no differentiation or conditions for selection. The lack of any usage context forces the agent to infer applicability, which is inadequate.

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