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

No annotations are provided, so the description carries the full burden. It only reveals that the tool returns the current UTC timestamp but does not disclose that the many input parameters are discarded or do not affect the result. An agent could mistakenly believe these parameters influence the call.

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 short sentence with no wasted words, appropriately sized for a trivial tool. It is front-loaded but omits a note about the unrelated parameters, which would have made it more complete.

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?

Despite the large, unrelated input schema, the description explains nothing about why these parameters exist, what the exact return value looks like, or any call conventions. The mismatch between the tool's stated purpose and its schema makes this definition incomplete for an agent.

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 input schema documents every parameter, most with descriptions like 'discarded after the shape check' or 'no disk access,' so schema coverage is essentially complete. The description adds no meaning beyond the schema, but the schema itself clarifies the parameters' role; therefore the baseline score of 3 is appropriate.

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' states a clear verb and resource, making the core function unambiguous. It distinguishes from the sibling 'timezone' by focusing on UTC, though it does not mention the output format or that the input parameters are irrelevant.

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 the many other siblings. It is a bare statement with no contextual cues for selection.

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