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

The description does not mention any side effects, permissions, or read-only nature. Since there are no annotations, the description carries the full burden, and it fails to disclose whether the tool performs any writes or has network dependencies beyond reading time.

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 concise sentence that directly communicates the core functionality. No unnecessary words or redundant information are present.

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 presence of three unexplained parameters creates significant context gaps. While the core purpose is clear, the tool's overall contract is confusing, and there is no output schema or description of the return format, leaving an agent unsure about expected results.

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 schema defines four parameters (url, host, json, zone), but the description only explains 'zone'. The other three parameters are entirely unexplained and appear irrelevant to the stated purpose. With only 25% schema coverage and no compensating detail, an agent cannot determine how or whether to supply url, host, or json.

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 unambiguously states the tool's function: returning the current time for a named IANA timezone. It is specific enough to distinguish from sibling tools like utc-time, 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?

No guidance is provided on when to use this tool versus alternatives such as utc-time or other time-related tools. The description implies usage for timezone-specific queries, but does not state any conditions, prerequisites, or exclusions.

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