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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says 'Current time', implying a read-only lookup, but it does not describe the return format, invalid-zone behavior, or any side effects. This is sparse given the unusual input schema.

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 words. It is appropriately concise for a simple operation, although the mismatch with the schema means brevity comes at the cost of needed guidance.

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?

The tool has no annotations and no output schema, and the input schema contains nine unrelated optional parameters. The description gives no indication of which parameter should receive the IANA timezone name, no example, and no output expectations. An agent cannot reliably invoke this tool correctly from the provided definition.

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 has 9 parameters with descriptions, so coverage is high, but the descriptions are irrelevant to the tool's purpose: ref, url, city, feed, host, json, path, and query are all described as unrelated checks or discarded inputs. There is no parameter representing the named IANA timezone, and the description does not map its intent to any schema field. The schema actively misleads an agent trying to call 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 states the tool's function clearly: returning the current time for a named IANA timezone. It is distinguishable from sibling tools like 'utc-time' and 'iana-zones' by the 'named IANA timezone' qualifier, but it does not explicitly differentiate itself by name.

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 when to use the tool: when the current time in a specific IANA timezone is needed. However, it gives no explicit guidance about when not to use it, no alternatives, and no context about preferred sibling tools.

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