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

With no annotations provided, the description must fully disclose behavioral traits, but it reveals nothing about side effects, return values, error handling, or state changes. The schema hints that many parameters are 'discarded after' checks, implying validation behavior, but the description does not clarify this. No behavioral contract is communicated.

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 single sentence is minimal, but it is under-specified rather than concise. It omits critical information, and the lack of structure (e.g., bulleted usage, parameter context) makes it unhelpful. Conciseness should not come at the expense of necessary detail.

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 parameters, no output schema, and no annotations, a complete description is essential. This description provides almost no context: it does not explain why the parameters are present, what the tool returns, or how it fits into a workflow. It is wholly inadequate for correct invocation.

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?

Although schema_description_coverage is 100%, the description adds no meaning to the parameters. The nine parameters (ref, url, city, feed, host, json, path, zone, query) are diverse and unrelated to the stated purpose of 'IANA timezone names.' The description does not explain how these parameters are used or why they are relevant, leaving the agent to infer from field names alone.

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 'Common IANA timezone names for clock calls' names a resource (timezone names) and a domain (clock calls) but never states what action the tool performs—does it list, validate, or resolve names? It does not distinguish itself from sibling tools like `timezone`, `utc-time`, or `weather-hint`, all of which are time-related but have clearer purposes.

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 usage guidance is provided. There is no statement about when to invoke this tool, when not to use it, or how it relates to alternatives such as `timezone` or `utc-time`. An agent would have no basis to select this tool over its siblings.

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