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

With no annotations, the description carries the full behavioral burden; the wording '列出' does imply a safe read-only lookup, and the linkage to schoolKeyid tells the agent what the results feed into. It says nothing about whether results are paginated, ordered, or whether the optional township scope must be pre-validated via list_areas (that hint lives only in the schema), so behavioral disclosure is adequate but thin.

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?

A single front-loaded sentence with the resource, the scoping dimensions, and the downstream use in that order. No filler, no repetition of the title, and nothing an agent must read twice.

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 three-parameter lookup with a fully documented schema and no output schema, the description covers purpose, scope, and intended consumption, which is most of what an agent needs to call it correctly. The only meaningful gap is the shape of the returned list (names plus keyids), which is implied rather than stated.

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 description coverage is 100%, including an enum for schoolType and a documented ALL/「縣市|鄉鎮」 format for area, so the schema already does the heavy lifting. The description only paraphrases that township narrowing is optional ('可再限定鄉鎮') without adding format or edge-case meaning beyond the schema, so the baseline 3 applies.

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 verb (列出) and resource (學校), scopes it by city/township and school type, and ties it to a concrete downstream consumer (get_school_hotspots 的 schoolKeyid). This makes it clearly distinguishable from siblings such as get_school_hotspots or get_school_rank, which consume rather than produce the key.

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?

It states the operational context explicitly: use this to obtain a schoolKeyid for get_school_hotspots, which is effectively a prerequisite-step instruction. It stops short of any exclusion (e.g. 'do not use for accident statistics – use get_school_accident_points'), so it is clear but not complete guidance.

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