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 ('current UTC timestamp') and does not reveal that the 9 parameters are validated and discarded, that the tool has no side effects, or any other behavioral details such as auth, rate limits, or return format. This is a significant omission.

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 concise (one short sentence) and not bloated, but it is under-specified. It fails to earn its place by omitting critical context about parameters and behavior, making it minimally acceptable rather than well-structured.

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?

For a tool with 9 optional parameters, no output schema, and no annotations, the description is woefully incomplete. It does not explain the purpose of the parameters, the return format, any validation behavior, or when to use the tool, leaving an agent with insufficient information to call it 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?

Schema description coverage is 100%, with each parameter clearly documented in the input schema (e.g., 'Git ref name; discarded after the shape check'). The description adds no parameter information, so it meets the baseline of 3 but does not enhance understanding beyond what the schema already provides.

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's function, but it does not differentiate from sibling tools like 'timezone' or 'iana-zones', and the presence of 9 seemingly unrelated parameters (ref, url, city, etc.) without any explanation in the description creates confusion about the tool's actual purpose and scope.

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?

There is no guidance on when to use this tool versus alternatives, nor any mention of exclusions or conditions. The description is a single phrase with no context about appropriate use cases, making it impossible for an agent to decide when to select this tool over siblings.

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