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

No annotations are provided, so the description carries the burden of disclosing behavior. It states 'Current time' implying a read operation, but it does not mention that all input parameters except 'zone' are discarded, nor does it cover return format, error handling, or whether it accesses external systems. The schema's many irrelevant parameters could mislead an agent.

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 efficient sentence with no wasted words. It is appropriately concise for a simple tool, though it could add a note about the 'zone' parameter without sacrificing brevity.

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?

Given the tool has 10 parameters, of which only one is used, and no output schema, the description is incomplete. It fails to inform the agent about the parameter mismatch or the return value, leaving significant ambiguity for correct invocation.

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 description adds nothing about parameter usage. It does not specify that only 'zone' is relevant, while the other nine parameters are misleadingly included. An agent could waste effort providing 'url', 'city', etc., without knowing they are ignored.

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 tool returns the current time for a given IANA timezone. It is specific about the resource (timezone) and the result, and implicitly distinguishes from siblings like 'utc-time' (UTC only) and 'iana-zones' (list of 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?

No guidance is provided on when to use this tool versus alternatives. For example, it could mention that 'utc-time' is for UTC, or that a valid zone name from 'iana-zones' is needed. The context is implied but not explicit.

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