World clock & meeting planner

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

Annotations already declare readOnly/openWorld=false/idempotent, and the description usefully corroborates this with 'Uses Node's ICU time-zone data; no network', which tells the agent results are deterministic and offline. Because there is no output schema, the enumeration of returned fields (local time, date, weekday, UTC offset, difference, day/night and working-hours flags, planner bands) adds real value beyond annotations.

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?

Purpose and planner capability are front-loaded in the first two sentences, followed by input-format guidance and a provenance note. Every sentence carries information; nothing is redundant padding.

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 no output schema and six parameters, the description adequately explains what comes back (per-zone fields, planner bands, overlap hours) and what inputs look like. It stops short of describing edge cases such as invalid zone names or the 50-item cap, but nothing essential for a correct call is missing.

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 100%, so all six parameters are already documented. The description only reinforces zone input format (IANA ids or city names) and the notion of a home zone used for differences and the planner day; it adds little syntax or constraint detail beyond the schema.

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?

Opens with a specific verb+resource ('Current (or any given) time in a list of time zones or cities') and then names the second capability, the 24-hour meeting planner. It clearly separates itself from siblings like time_convert by emphasizing multi-zone listing plus planner bands, though it never names an alternative explicitly.

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?

Usage is implied by the description of outputs and the default behaviors ('Current (or any given) time'), so an agent can infer this is the tool for multi-zone/meeting-scheduling queries. However, there is no explicit when-to-use vs. time_convert or calc_date_diff, and no exclusions or prerequisites.

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