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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered and the description only has to add context. It adds nothing about the response (forecast horizon, time granularity) or error behavior, which are the remaining unknowns for a network-backed, open-world read.

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 sentences, front-loaded with purpose followed by the invocation constraint; no filler, no repetition of the title.

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 simple read-only tool with two fully described parameters, the definition covers what an agent needs to call it correctly. With no output schema, a brief note on what the forecast returns (e.g. per-day or per-hour entries) would close the last gap.

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 both parameters are already documented, including pointing to cuaca_search for adm4 and the representative-village behavior for kabupaten_id. The description nonetheless contributes the mutual-exclusivity/one-required constraint that the schema's empty required list does not express, which is real added meaning.

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?

"Get weather forecast for an Indonesian location" names a specific verb (get) and resource (weather forecast) plus geographic scope, so the purpose is unambiguous. It does not, however, distinguish itself from the sibling cuaca_search, which is only referenced inside the schema, so an agent must infer the difference.

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?

The description gives a hard invocation rule (exactly one of adm4 or kabupaten_id), which is genuinely useful usage guidance. It stops short of stating when to prefer this over cuaca_search or what happens with an invalid/unknown code.

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