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 traits such as side effects, return format, or whether it is read-only. The noun-phrase description gives no insight into what happens when the tool is invoked, leaving the agent to guess.

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 unnecessary words. However, its brevity borders on under-specification, and it lacks any structure or key information that would help an agent understand the tool's purpose or usage. It is efficient but not sufficiently informative.

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 and no annotations, the description is far from complete. It does not explain the tool's overall function, what it returns, or how the parameters are used together. The schema documents each parameter but the description fails to tie them into a coherent operation, making the tool 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?

Schema description coverage is 100%, so all 9 parameters are documented in the schema. The description itself adds no additional meaning beyond the schema, so it meets the baseline of 3 without exceeding it. The tool name suggests a relation to timezones, but the description does not clarify how parameters like 'ref' or 'url' relate to timezone names.

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 that the tool provides 'Common IANA timezone names for clock calls', indicating it is a data resource for timezone names. However, it does not specify the actual operation (e.g., returns a list, validates a name, etc.), leaving the purpose somewhat vague. It is not a tautology but lacks a clear verb and resource action.

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 offers no guidance on when to use this tool versus alternatives like 'timezone' or 'utc-time'. It only mentions 'for clock calls' without explaining when this tool is the appropriate choice or what distinguishes it from siblings.

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