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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states only that it returns the current local time, but does not disclose whether it makes network calls, whether the result is deterministic, or what the output format is. For a simple read-only time tool, this is minimal but arguably sufficient; however, the lack of any mention of side effects, performance, or output structure leaves 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, concise sentence that states the core function with no wasted words. It is front-loaded with the primary action and resource. For a simple tool, this is appropriately minimal.

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 9 parameters, none required, and no output schema. The description does not explain why these parameters exist for a time tool, nor does it mention the return format or how the tool should be invoked. There is no guidance on which parameters to provide or ignore, and the presence of unrelated parameters (e.g., 'url', 'json', 'path') suggests the tool may be a generic utility that only incidentally reports Guam time. The description is grossly incomplete for an agent to use this tool 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?

The schema covers all 9 parameters with descriptions (100% coverage), so the baseline is 3. The tool description does not add any parameter-specific meaning; it does not explain how parameters like 'ref', 'url', or 'city' relate to getting the current time. Since the schema already documents each parameter, the description need not repeat, but it also does not clarify the role of these seemingly unrelated parameters in the context of a time lookup.

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 a clear verb ('Current local time') and a specific resource ('Pacific/Guam'). It is unambiguous about what the tool does, but it does not differentiate from sibling tools like 'timezone' or 'utc-time', which likely serve similar purposes. The specificity of the timezone name provides some distinction, but the description could explicitly note that it is Guam-specific.

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 guidance is given on when to use this tool versus alternatives. The description implies it is for Pacific/Guam time, but it does not state when one would choose this over 'timezone' or 'utc-time'. There is no mention of exclusions or alternative selection criteria, leaving the agent to infer usage from the tool name.

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