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

With no annotations, the description carries the full behavioral burden, but it only says 'Current time...' and provides no detail on return format, invalid-zone handling, or whether date/offset is included. Worse, the input schema is filled with unrelated 'discarded after' parameters, so the actual behavior is not transparent.

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 its brevity contributes to the omission of critical invocation details.

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 9-parameter tool with no annotations and no output schema, this description is grossly incomplete and actually inconsistent with the schema. An agent cannot determine which parameter to populate to get the time in an IANA timezone, making the tool effectively uncallable as documented.

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?

The schema parameters are overwhelmingly unrelated to the described tool: ref, url, city, feed, host, json, path, and query are each described for other purposes, and none accepts a timezone ID. The description promises a 'named IANA timezone' input, but no such parameter exists and all parameters are optional.

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 exactly what the tool returns: the current time in a named IANA timezone. This is specific and distinguishes it from siblings like utc-time and iana-zones, though it does not mention them explicitly.

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 tool should be used when an agent needs the current time in a specific IANA timezone rather than UTC or a list of zones. However, it never explicitly states when to use it versus alternatives or gives exclusion criteria.

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