timezone

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

With no annotations, the description carries the full burden and does meaningful work: it declares the exact return fields, the $0.002 USDC per-call cost, and a p99 latency of 200ms — all behavior an agent cannot infer from the schema. It omits failure behavior for unresolvable locations, so it is not a 5.

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?

One dense, front-loaded paragraph: capability first, then use cases, then the parameter, then cost/latency. Every clause carries information an agent can act on, with no filler or repetition.

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?

There is no output schema, so the description must name the return values — and it does (IANA timezone, local time, UTC offset, DST flag, weekday). Combined with the usage triggers and the single documented parameter, an agent has everything needed to call and interpret this tool.

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% for the single 'location' parameter, so the schema already documents the type and format. The description's example values ('Tokyo', '35.68,139.69') mirror the schema's 'City name or lat,lon' rather than adding new syntax. 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?

States a precise verb+resource: 'Resolve a city name or coordinates to its IANA timezone and return the current local time, UTC offset, DST flag and weekday.' The scope is narrow enough that an agent won't confuse it with siblings like geocode or holidays. It stops short of naming an adjacent tool it must not be used for, so it lands at 4 rather than 5.

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?

Gives concrete when-to-use triggers: scheduling across regions, 'what time is it in X', normalizing timestamps. That is clear contextual guidance with no misleading claims. No explicit exclusions or named alternatives are given, so it is a solid 4, not a 5.

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