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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful context beyond annotations: the JMA source, the coverage of all 58 offices plus subordinate place names, and the relationship to sibling tools. It stops short of describing failure behavior for unknown inputs, but that is minor for this resolver.

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?

Three tight sentences: purpose, source/coverage, and usage guidance. Every sentence earns its place, the essential purpose is front-loaded, and there is no redundant or filler language.

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 single-parameter resolver, the description covers the input forms, the output purpose, the data source, scope coverage, and the alternative of letting sibling tools resolve internally. No output schema exists, but the description clearly states what the tool returns (a raw office code), which is sufficient.

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 the baseline is 3. The description adds value by expanding the accepted input universe (English romaji, Japanese, area codes) with concrete examples like '大阪' and by clarifying that every prefecture, region, city, ward, and town JMA names is covered. This goes beyond the schema's brief examples.

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 uses a specific verb ('Resolve') with a clear input (Japanese place name or JMA area code) and output (JMA forecast OFFICE code). It distinguishes itself from jma_forecast and jma_warnings by stating they can resolve internally, so an agent knows exactly what this tool adds.

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 explicitly says 'Use this when you need the raw office code, or just pass the place name straight into jma_forecast / jma_warnings — they resolve internally.' This directly addresses when to choose this tool versus its siblings.

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