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

With no annotations, the description carries the full burden of behavioral disclosure. It discloses no behavior: it does not state that the tool returns a static list, whether parameters are ignored, what the output looks like, or whether there are side effects.

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 one short sentence with no filler, and the key domain ('clock calls') is placed at the end. It is concise, though the brevity sacrifices needed 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?

For a tool with no output schema and no annotations, this description is incomplete: it does not state the return value, whether any parameters affect the result, or how the zones should be passed to clock/timezone calls. The agent could call it, but would not know what to do with the result.

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 coverage is 100%, but the parameter descriptions describe generic validation/hint fields (e.g., Git ref, URL, city, feed, JSON, path) that are unrelated to IANA timezone names. The tool description adds no mapping between these parameters and the tool's behavior, so the schema is more confusing than helpful for this tool.

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 identifies the resource (IANA timezone names) and context (clock calls), but it is a noun phrase with no verb; it doesn't explicitly say whether the tool lists, validates, or returns these names. This is barely more than a gloss on the tool name 'iana-zones'.

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?

'For clock calls' implies a use context, but there is no guidance about when to prefer this tool over siblings such as 'timezone' or 'utc-time', nor any exclusion criteria. An agent must infer the workflow.

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