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

Annotations already indicate readOnlyHint=true, idempotentHint=true, destructiveHint=false, which cover safety and side effects. The description adds no extra behavioral context such as valid time zone formats, handling of DST ambiguity (despite the dstAmbiguity param), or output structure. Annotations carry the burden adequately, so a score of 2 reflects minimal added value.

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 sentence of 5 words—maximally concise but at the expense of informativeness. It earns a middle score because conciseness is achieved but critical details are omitted.

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?

Despite having an output schema, the description does not mention return values or behavior (e.g., does it return the time at both zones?). With 4 parameters including DST ambiguity handling, the description is too sparse to fully inform an agent about input/output expectations. Siblings increase the need for clarity, which is not met.

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 coverage is 0%: no property descriptions exist in the schema. The description 'Convert datetime between zones' provides no information about parameter formats (e.g., dateTime format, time zone naming), required vs optional status, or the meaning of dstAmbiguity. This is a critical gap given the lack of schema descriptions.

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 'Convert datetime between zones' clearly states the action (convert), the resource (datetime), and the scope (between zones). It distinguishes from siblings like 'current_time' and 'translate_to_iso' by focusing on conversion between arbitrary zones rather than obtaining current time or formatting. However, it does not explicitly contrast with related tools.

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?

No guidance is provided on when to use this tool versus alternatives. Siblings include multiple time-related tools (current_time, current_iso_zoned_date_time, translate_to_iso, list_zones), but the description gives no context about prerequisites, typical use cases, or exclusions.

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