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

With no annotations, the description carries full responsibility for disclosing behavior. It does not mention that the tool accepts and discards parameters, has no side effects, or returns a timestamp format. The unusual input schema (URLs, cities, JSON, paths) is completely unexplained, leaving the agent in the dark about how the tool actually behaves.

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, front-loaded phrase with zero wasted words. It is appropriately sized for a tool with such a simple purpose, even though it sacrifices contextual detail.

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 appears trivial, but the presence of seven unrelated, optional-looking parameters makes the description inadequate. An agent cannot tell whether any parameter is required, why they exist, or whether the tool returns something beyond a timestamp. The lack of an output schema and any note about parameter handling leaves significant ambiguity for a tool that should be one line.

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 descriptions are unusually detailed, explicitly stating that each property is 'discarded' after the call or check, so schema coverage is effectively 100%. The description adds no additional meaning about how parameters relate to the tool's function, but the schema itself supplies the necessary semantics, yielding the baseline score.

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 specific resource (UTC timestamp) and an implied verb (return/provide), making the primary action clear. It is naturally distinguished from siblings like 'timezone' and 'iana-zones', though it does not explicitly name 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?

There is no guidance about when to use this tool versus alternatives like 'timezone' or 'calc-eval', nor does it mention that the tool ignores all input parameters. An agent must infer the intended use from the name and one-line description alone.

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