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

With no annotations, the description carries the behavioral burden. It adds useful facts: no API key is needed and results arrive in one call. However, it does not explicitly state that the operation is read-only or what happens when the place is not found, so some behavioral risk remains unaddressed.

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?

Four short sentences each add distinct information: input form, return payload, auth requirement, and routing to siblings. The examples are packed into the first sentence without bloat, and there is no repetition of schema details.

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?

Even though there is no output schema, the description lists the full return payload with units (km), mountpoint, host, and the 5-digit municipality code. It lacks only minor details like ambiguous-name behavior and lang output effect, which keeps it slightly below complete.

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%; q is documented in the schema, and the description adds concrete examples (帯広, Obihiro, 京都市の基準局) and signals that extra words like 基準局/警報/near are accepted. But lang is mentioned only as an enum in the schema; the description never explains how the response language differs, leaving that parameter under-specified.

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?

Description states a concrete resource (a Japanese place) and exactly what the one-shot call returns: municipality code, JMA warnings, nearest RTK base station, and page URLs. It also distinguishes itself from the sibling detail tools by saying 'Use this first' and pointing to here/rtk_bases_near.

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?

Explicitly says 'Use this first when a user asks about a Japanese place; call here/rtk_bases_near for detail.' This gives a clear trigger condition and names the alternatives for follow-up, so an agent knows when to invoke 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.