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

Annotations are entirely absent, so the description carries the full burden of behavioral disclosure. It states the output but does not mention that all 9 parameters are effectively ignored (per schema descriptions they are 'discarded'), nor does it describe any side effects, return format, or constraints. For a tool that accepts parameters but discards them, this is a notable omission that could lead an agent to mistakenly think parameters affect the result.

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, achieving high clarity in a compact form. However, given the tool's 9 parameters, the brevity borders on under-specification, though that issue falls under completeness rather than conciseness. The structure is appropriately front-loaded with the core purpose.

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 optional parameters, no output schema, and no annotations. The description is extremely sparse, providing no information about the parameters being ignored, the return format, or any behavioral nuances. An agent calling this tool would have to rely solely on the schema, which does describe each parameter as discarded, but the description itself fails to convey that the tool effectively ignores all inputs, making it potentially confusing. This is inadequate for a tool with this complexity.

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 every parameter is documented in the schema (e.g., 'Git ref name; discarded after the shape check'). The tool description adds no additional meaning beyond the schema. Since the schema already explains the parameters clearly, a baseline score of 3 is appropriate; the description neither enhances nor detracts from parameter understanding.

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 'Current UTC timestamp' clearly states the tool returns the current UTC time, with a specific verb and resource. It is not a tautology, but it does not differentiate from sibling tools like 'timezone' or 'iana-zones', which might also involve time retrieval. The name 'utc-time' adds specificity, but the description alone does not clarify how it differs from those alternatives.

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 provided on when to use this tool versus its siblings. There is no mention of scenarios, exclusions, or alternatives. The description is a bare statement of functionality, leaving the agent to infer usage from the name alone.

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