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

With no annotations, the description bears the full burden of disclosing behavior. It only says 'Current time' and offers no information about the return format, side effects, or how the many other parameters are handled (e.g., that they are discarded). This is extremely opaque, especially given the parameter descriptions mention 'discarded after the shape check' but the tool description does not.

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 short sentence, which is efficient in wording, but it is under-specified for a tool with nine parameters and unclear scope. This is under-specification, not conciseness, because critical information about the tool's full behavior is missing.

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 nine parameters, no annotations, and no output schema, so the description must be comprehensive to be usable. It fails to explain the purpose of the non-timezone parameters, lacks any usage context, and says nothing about the output. The description is grossly incomplete for the tool's complexity.

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 description coverage is 100%, so the schema itself documents all parameters, including their disposal behavior. The description adds no parameter-level meaning beyond the schema, so it remains at the baseline of 3. It neither helps nor harms.

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 specific action: get the current time for a named IANA timezone. However, it fails to differentiate from the sibling tool 'utc-time' and does not account for the nine unrelated parameters in the schema, leaving the tool's actual scope ambiguous. The verb-resource is clear but the overall purpose is muddied by the schema mismatch.

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?

There is no guidance on when to use this tool versus alternatives like 'utc-time' for UTC or 'iana-zones' for listing zones. No conditions, prerequisites, or exclusions are provided, so an agent has no basis to choose this tool over siblings.

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