Download File from Kintone

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

With no annotations provided, the description carries the behavioral disclosure burden. It explicitly discloses the local filesystem side effect, the return value, and the required permissions and environment setup. It does not mention overwrite behavior or failure modes, but the most important behavioral traits are covered.

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 compact sentences with no filler. The first sentence states the action and return value, and the second lists prerequisites; it does not repeat schema details or add unnecessary context.

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 simple two-parameter tool with an output schema and fully documented parameters, this description is largely complete: behavior, return value, and prerequisites are all included. Minor omissions such as overwrite policy and error behavior prevent a perfect score, but the agent has enough to select and call the tool 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%, and both parameters are already well documented: fileKey explains its source and fileName explains naming plus automatic extension detection. The description adds the download-directory context but no additional parameter-level meaning, so the schema does the heavy lifting.

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 the specific action (download), the resource (a file identified by fileKey), and the destination (the configured download directory). This clearly distinguishes it from sibling tools, which concern app settings, form layouts, and record operations rather than file retrieval.

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 states the prerequisite environment variable and required permissions, giving clear conditions for successful use. It implies the appropriate context—after obtaining a fileKey from record retrieval or upload—and no sibling tool provides file download, so an explicit 'use this instead of X' exclusion is not necessary.

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