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

No annotations are provided, and the description does not disclose any behavioral aspects such as side effects, network calls, or whether the tool is read-only. It simply states the function without transparency about potential external dependencies or side effects.

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, concise sentence with no redundant words. It is efficient but perhaps too terse, omitting useful context about parameters and usage. Still, it scores well on brevity.

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 apparent simplicity, the description lacks essential context such as the expected output format, error behavior for invalid timezone names, and guidance on the many extraneous parameters. The absence of an output schema makes this incompleteness more detrimental, as the agent cannot infer what the tool returns.

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 the schema descriptions cover 100% of parameters, the description mentions only 'IANA timezone name' while the tool accepts 9 parameters, most of which seem unrelated (ref, url, city, feed, host, json, path, query). The description does little to clarify which parameters are actually used or how they relate to the stated purpose, leaving the large parameter list 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 clearly states the tool's function: returning the current time for a named IANA timezone. The verb 'current time' and resource 'IANA timezone' are specific, and the tool name 'timezone' aligns with the description. However, it does not distinguish itself from the sibling 'utc-time' or 'iana-zones' tools beyond the name.

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 gives no guidance on when to use this tool versus alternatives like 'utc-time' or 'iana-zones'. There is no mention of use cases, prerequisites, or conditions that would make this tool preferable.

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