Japan Weather Warnings MCP

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

With no annotations, the description carries the full behavioral burden. 'Raw' and 'full ... JSON' hint that output is unfiltered and potentially large, but there is no mention of the subscription/auth requirement (only implied by 'PRO.'), response size, error behavior, or whether office codes and prefecture names behave differently.

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 short sentence, front-loaded with the tier marker and the return payload, with zero filler. It is efficient but arguably too terse to earn its place as the sole guidance.

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?

No annotations, no output schema, and an undefined acronym (JMA) leave the agent without a picture of what comes back or what 'raw' entails. For a PRO-gated data tool with a 2-param schema and zero structured documentation, the description should do considerably more.

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 50%: access_token is documented in the schema, prefecture is a bare string. The description partially compensates by noting that 'prefecture' can also be an office code, which is real added meaning beyond the schema, but it gives no format examples or how disambiguation works.

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 the resource returned (full JMA warning JSON) and the scoping key (one prefecture / office code), which is more specific than the name alone. However, it never distinguishes itself from the sibling 'warnings_for', so an agent cannot tell why it would pick 'raw' over the sibling without guessing that 'raw' means unfiltered/verbatim.

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?

No when-to-use or when-not-to-use guidance is given. The only routing signal is the 'PRO.' prefix, which implies a paid tier but does not explain when to prefer this over 'warnings_for' or 'watchlist'.

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

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

With no annotations, the description carries the burden, and it does disclose two useful traits: the call is free and returns 'current' (not historical) data. It omits whether the tool is read-only (strongly implied by 'warnings'), the response shape, and any failure behavior for unknown prefectures.

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 sentence, front-loaded with the key differentiator ('FREE') and immediately followed by what the tool returns and the accepted input forms. Nothing is wasted.

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?

Given a one-param, no-annotation, no-output-schema tool, the description covers the essential facts: cost, currency of data, accepted input forms, and default. Return-value structure is the only material omission, and it is minor for a simple list endpoint.

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 0% for the single optional parameter, but the description compensates well by stating it accepts either a prefecture name or an office code, and by giving the default value (Tokyo / 130000) with a concrete example code format.

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 names a specific resource (current JMA weather warnings) and its scoping input, which is clear enough to distinguish from a raw feed. It never names or contrasts the siblings raw_warning or watchlist, so an agent must infer the boundary itself.

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?

There is no guidance on when to choose this over raw_warning or watchlist, nor any stated preconditions. The only selection hint is the word 'FREE', which implies a cost trade-off but doesn't route the agent explicitly.

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

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

No annotations exist, so the description carries the full disclosure burden and largely drops it. The 'PRO' marker usefully hints that a paid/authenticated tier is required, and the 10-item cap is a real constraint, but there is no mention of return shape, freshness, or error behavior when exceeding the limit.

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 fragments with no padding and the key constraint (10 items) front-loaded. The terse 'PRO.' opener is efficient though slightly cryptic as a lead token.

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 tool with no annotations and no output schema, the description is far too thin — an agent cannot tell what a 'warning' contains, whether results are live, or what happens at the 10-item boundary. The missing verb and absent usage routing leave it substantially under-specified.

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 50%: access_token is documented in the schema, while prefectures is undocumented there. The description partially compensates by clarifying that the array holds prefectures or office codes and is capped at 10 items, which is genuine meaning beyond the schema — but it does not specify format or whether codes and prefecture names are interchangeable.

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?

It names the resource (warnings) and the scope (up to 10 prefectures / office codes at once), which hints at batch behavior distinct from siblings raw_warning and warnings_for. However, there is no verb — it is a noun phrase plus a marketing tag — so the agent must infer that it retrieves warnings rather than subscribes to or manages them.

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?

No when-to-use or when-not guidance, and no comparison to sibling tools such as warnings_for or raw_warning. The only discriminating signal is the implied batching and the 'PRO' tier tag, which the agent must interpret itself.

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