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 behavioral disclosure. Saying 'Current time' only restates the core function and does not disclose output shape, failure behavior, rate limits, or that most parameters are discarded.

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, front-loaded sentence with no filler. It is concise, but the brevity is achieved by omitting necessary contextual information.

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?

With a seven-parameter schema full of 'discarded' parameters, no annotations, and no output schema, the description is far too thin. It does not explain how to provide a 'named IANA timezone' or what the tool returns, making correct invocation nearly impossible.

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?

All seven schema parameters have descriptions, so the baseline is higher, but the description introduces 'IANA timezone' while no parameter description references timezones. The description thus fails to map the tool's purpose to any specific input, leaving the agent to guess among ref, url, city, feed, host, json, and path.

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 states a concrete action: returning the current time for a named IANA timezone. This semantically distinguishes it from siblings like utc-time and iana-zones, though it does not name them. The clarity is weakened by the fact that no schema parameter obviously represents a timezone.

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 provides no explicit guidance on when to use this tool versus alternatives such as utc-time or iana-zones. It also does not mention prerequisites like the expected timezone format or that many schema parameters are discarded.

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