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 does not explain that many parameters are ignored or discarded, nor does it describe the output format or any side effects. The schema hints at discarding inputs, but the description itself is silent, leaving significant behavioral gaps.

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 sentence, which is concise, but it is too terse and fails to convey essential information. The sentence is not front-loaded with actionable content and leaves out critical details about the tool's operation, making it under-specified rather than efficiently 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?

The tool has nine parameters, no required fields, and no output schema. The description does not explain what the tool returns, how the parameters influence the result, or why they are all optional. Given the complexity and lack of structured output information, the description is incomplete and inadequate for an agent to use 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%, and each parameter has a descriptive comment (e.g., 'discarded after the shape check'). The tool description adds no additional meaning about how parameters relate to the timezone list. Baseline 3 is appropriate since the schema already documents the parameters, though the mismatch between the tool's purpose and parameter set remains confusing.

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 'Common IANA timezone names for clock calls,' which implies the tool provides a list of timezone names. However, it lacks a clear verb (like 'returns' or 'provides') and does not differentiate itself from siblings such as 'timezone' or 'utc-time'. The ambiguity is heightened by the presence of nine unrelated parameters in the schema, making the tool's actual function unclear.

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 only mentions 'for clock calls,' which is too vague to establish selection criteria. No exclusions or explicit conditions are provided, leaving the agent without direction on when this tool is appropriate.

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