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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description does add one genuine behavioral detail not in the annotations (date rollover handling) and mentions the return shape, but it says nothing about edge cases like invalid offsets or DST-free assumptions.

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?

Four short sentences, front-loaded with the core action; each earns its place except the trailing pointer to list_bundles, which is mildly promotional. Nothing is padded or repeated.

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?

With an output schema present the description needn't explain returns, and its coverage of purpose and inputs is adequate for a three-parameter calculator. The gap is routing: among dozens of adjacent time/conversion siblings it gives no basis for choosing this tool over convert_time or calculate_timezone_offset.

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 all three parameters are fully documented in the schema. The description's 'Inputs: time, from-utc, to-utc' merely restates parameter names and adds no format, range, or offset-sign meaning beyond the schema. Baseline 3 applies.

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 gives a specific verb and resource ('Convert a time between two UTC offsets') plus a meaningful qualifier ('accounting for date rollover'), so the operation is unambiguous. It falls short of a 5 because it never distinguishes itself from very close siblings like calculate_timezone_offset, calculate_time_zone_difference, and convert_time.

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?

'Use for international meetings' supplies an implied context but no when-not guidance and no explicit alternative among the many time/timezone siblings. An agent must guess whether this or calculate_time_zone_difference is the right call.

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