Get forecast

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

With no annotations, the description carries the full burden. It usefully discloses that no API key is required and that geocoding is performed internally (a hidden side effect/precondition), but says nothing about failure modes for unknown or ambiguous cities, rate limits, or the units/timezone of the returned data.

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?

Two short sentences, front-loaded with the action and followed by the auth reassurance. Every clause carries information; no filler.

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?

For a two-parameter read tool with no output schema and no annotations, the description covers purpose and auth but leaves the return shape only loosely sketched ('current conditions and a short daily forecast'). Units, timezone, and structure of the forecast days are unstated, which an agent would need before interpreting results.

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%, with both city and days (1-7, default 3) fully documented in-schema. The description adds no parameter-level detail such as date semantics or how multi-day results are keyed, so it does not exceed the schema baseline.

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 specific verb and resource: returns current conditions plus a short daily forecast from Open-Meteo. It also clarifies that geocoding happens internally, which implicitly distinguishes it from the sibling geocode_city, though it never names that tool 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?

Mentions the internal geocoding step, which hints that the agent need not call geocode_city first, but there is no explicit when-to-use or when-not-to-use guidance against the sibling. Usage context is implied rather than stated.

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