List timezones

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

The annotations already mark the tool as readOnly and not openWorld, and the description adds the IANA-zone scope and optional filtering. It does not disclose additional behavioral traits like result-size caps, matching semantics, or side effects, but nothing here contradicts the annotations.

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 well-ordered sentence: core operation first, optional modifier appended. It contains no filler, no repetition of schema details, and every word contributes meaning.

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?

For a simple read-only list tool with an output schema and readOnlyHint, the basic call is clear. However, the sparse parameter semantics and lack of usage context mean an agent could call it but may misuse query or max_results. It is minimally viable, not fully complete.

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 0%, so the description needed to explain query and max_results. It only hints at filtering and is silent on max_results, query format, or matching behavior, leaving the agent to rely on parameter names and defaults.

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 uses a clear verb ('List'), a specific resource ('IANA zones'), and notes optional filtering. It is not a pure tautology, but it largely restates the title and doesn't explicitly contrast with sibling time tools like time_now or time_convert.

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 explicit when-to-use guidance, no exclusions, and no reference to sibling alternatives. The intended use is only implied by the verb 'list' and the readOnlyHint annotation, so an agent receives no help choosing this over time_now or time_convert.

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