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

With no annotations, the description must carry the behavioral burden, but it only states the output. It does not disclose that the optional parameters are discarded, that the call has no side effects, or what format the timestamp takes. The schema parameter descriptions hint at discarding, but the tool description itself omits these behavioral details.

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?

One sentence is concise and front-loaded, but it is under-specified for a tool with 9 optional parameters and no output schema. Brevity here comes at the cost of necessary nuance rather than trimming filler.

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 no output schema, no annotations, and 9 optional parameters, yet the description provides only a one-phrase output statement. An agent cannot tell the timestamp format, whether parameters are ignored, or how to relate the parameters to the output, making the description incomplete for correct invocation and understanding.

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 optional parameter has descriptive comments like 'discarded after the shape check' or 'no disk access', so the schema carries most parameter meaning. The description adds no clarity about why a UTC timestamp tool takes URL, city, JSON, and path params or whether they are all ignored.

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 identifies the returned resource and distinguishes it from datetime-helpers such as timezone or iana-zones. However, it does not explain how the 9 optional parameters relate to the purpose or differentiate it explicitly from sibling tools.

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 call this tool versus alternatives like timezone or other validation tools. The description says nothing about whether parameters are optional, irrelevant, or when to omit them, leaving the agent with no usage direction for a tool that accepts 9 unrelated-looking optional parameters.

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