ファイルの書き込み

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

The annotations already signal destructiveness (destructiveHint=true). The description adds valuable behavioral detail by explicitly stating that existing files are overwritten and that append=true appends instead. This goes beyond the annotation without contradicting it.

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, focused sentence that front-loads the core action and constraint, with a parenthetical clarifying the append option. No wasted words or redundancy with the schema.

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?

With annotations covering safety, the schema covering parameters, and an output schema present, the description covers the essential behavior (overwrite vs. append) and scope. Nothing critical is missing for a competent agent to invoke it correctly.

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%, so the parameters are already fully documented. The description adds minimal extra meaning beyond the schema, mainly reinforcing the overwrite/append behavior already visible in the schema defaults and descriptions.

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 the action ('書き込みます' — writes) and the resource ('ファイル' — file), and explicitly notes the allowed-folder scope. This sets it apart from sibling read/list tools without any ambiguity.

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 usage context is implied: it handles writes within the allowed folder, while siblings handle reading and listing. However, it does not explicitly mention when to prefer this tool over read_file, or what conditions would make writing inappropriate.

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