Get Current Time

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

The annotations (readOnlyHint=true, idempotentHint=true) already disclose safety and side-effect profiles. The description adds context that the time is returned in UTC and the IANA timezone can be specified or guessed. However, it does not elaborate on behavior such as error handling, default format, or the fact that repeated calls yield different times, leaving some transparency gaps.

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 concise sentence that immediately states the tool's core function. It is front-loaded and contains no filler or redundant 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?

The tool is simple, and the output schema likely covers return values, but the description lacks usage guidance and sibling differentiation. The absence of any mention of alternatives like get_timestamp creates a completeness gap, though the tool itself is well-scoped.

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 already documents both parameters. The description adds little beyond the schema, only weakly referencing the timezone parameter ('specified or guessed'). It does not enrich the meaning of the 'format' parameter, so baseline 3 is appropriate.

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 that the tool returns the current time in UTC and an IANA timezone. It uses a specific verb ('Returns') and identifies the resource ('current time'). However, it does not explicitly distinguish itself from sibling tools like get_timestamp, which might also return the current time in a different format.

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 guidance on when to use this tool versus alternatives. It only states what it does, without mentioning exclusions, prerequisites, or sibling tools. For example, an agent may not know whether to choose current_time or get_timestamp for a given task.

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