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

No annotations are provided, so the description carries the full burden of disclosing behavior. It only states the output (a timestamp) and says nothing about how the input parameters are handled, whether they are validated, discarded, or ignored. The schema's parameter descriptions mention 'discarded after the shape check', implying a validation step that the description omits, leaving the tool's actual behavior opaque.

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, clear sentence with no filler. It front-loads the core purpose immediately. This is maximally concise and efficient for the information it conveys.

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?

With 9 optional parameters and no output schema, the description is grossly incomplete. It fails to explain why these parameters exist, what happens if they are provided, whether the tool performs validation, or what the response format is. An agent cannot confidently call this tool with the given information.

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%, and each parameter already has a detailed description explaining its purpose and that it is discarded after a shape check. The tool description adds nothing about parameters, which is acceptable given the schema's completeness. However, it does not resolve the mismatch between the timestamp purpose and the parameter descriptions, so it neither enhances nor detracts from the schema's semantics.

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 returns the current UTC timestamp, a specific verb+resource. However, the input schema includes 9 optional parameters with descriptions implying shape checks and discarding behavior, which is not reflected in the description. This creates ambiguity about whether the tool does more than return a timestamp, so it is not fully distinct from its siblings.

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 provides no guidance on when to use this tool versus alternatives like 'timezone' or 'iana-zones'. There is no mention of prerequisites, exclusions, or context for selection. An agent receives zero routing information.

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