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

There are no annotations, so the description carries the full burden of disclosing side effects, safety, or internal behavior. It discloses none of this; it does not even state whether the tool returns data, performs a check, or simply provides a static list. The schema's repeated 'discarded' language suggests side-effect-free behavior, but the description itself is silent.

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 extremely short, which is superficially concise, but it is under-specified to the point of being unhelpful. It lacks an action verb, behavioral context, and usage guidance, so brevity is not serving the agent effectively.

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?

This tool has nine parameters, no annotations, no output schema, and a description that fails to explain what the tool does or what the agent should expect from a call. Given the complexity of the input schema and the need to disambiguate from 25 siblings, the description is far from complete.

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 individually documented, including notes on being discarded after checks. The description adds no parameter meaning, but the schema already does the heavy lifting, so the baseline 3 is appropriate.

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 is a noun phrase ('Common IANA timezone names for clock calls') with no verb indicating what the tool does—whether it lists, validates, resolves, or returns a timezone name. It names a resource domain but does not state an operation, and it does not distinguish itself from sibling tools like timezone, utc-time, or geo-hint.

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 only contextual hint is 'for clock calls,' which implies a relationship to time-related tools but gives no explicit guidance on when to choose this tool over timezone, utc-time, or any sibling. No exclusions, prerequisites, or alternative routing are provided.

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