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

With no annotations, the description must carry the behavioral burden. It states the basic read behavior but does not disclose the output format, behavior for invalid or missing timezone names, or whether the call is side-effect-free beyond what is obvious. No contradiction exists, but the disclosure is thin.

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?

A single sentence with no filler; the core behavior is front-loaded. Every word earns its place.

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 many optional parameters and no output schema, but the description does not specify return format, confirm that zone is the operative parameter, or explain the significance of the discarded fields. Relying on schema descriptions alone leaves meaningful ambiguity for an agent invoking the tool.

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%, so the baseline is 3; the schema already documents each parameter, including zone. The description adds little beyond the phrase 'named IANA timezone' and does not clarify which of the many parameters to populate or that zone is effectively required.

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 operation: returns the current time for a named IANA timezone. It distinguishes the tool from generic time lookups, but it does not explicitly call out siblings like utc-time or iana-zones, so it misses the top sibling-differentiation mark.

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 implies the use case: use this when an IANA timezone name is available and current local time is needed. There is no explicit when-not-to-use guidance or comparison with alternative tools such as utc-time or iana-zones, so it's only implicitly useful.

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