neighbors

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently states that it returns graph edges with line names and importantly discloses a limitation: it does not indicate whether specific trains stop. This is valuable context beyond a simple 'returns neighbors'. It does not mention side effects or read-only nature, but for a query tool this is acceptable.

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?

The description is two sentences with no waste. It front-loads the core purpose (returns adjacent stations with line names) and then adds the important caveat. All information earns its place.

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?

The description is complete for a simple one-parameter tool with no output schema. It explains what is returned (adjacent stations, line names) and a key limitation. It does not detail the exact response structure (e.g., objects with station/line fields) or handle error cases, but for a tool this simple, the description is adequately 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?

The input schema fully documents the parameter with a description ('駅名（例: 渋谷）'), so schema coverage is 100%. The description does not add additional parameter-specific meaning; it only elaborates on the output. Given the high schema coverage, a baseline of 3 is appropriate.

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 clearly states a specific verb ('返す' - returns), resource (adjacent stations on the track), and adds context (graph edges, line names). It also distinguishes itself from a generic 'neighbors' by specifying it's track-level adjacency, not train stops, which differentiates it from the sibling 'subgraph' tool.

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 provides context that it returns track adjacency but does not explicitly state when to use this tool versus the sibling 'subgraph'. There is no direct comparison or 'use this when' guidance. The note about train stops is a limitation, not usage guidance, so the usage is implied rather than stated.

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