append_file

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

No annotations are provided, so the description must carry all behavioral disclosure. It states the core mutation behavior and the prerequisite that the file exists, but it does not mention error handling, security implications, or other side effects. This is acceptable but not richly transparent.

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 extremely concise: one sentence for behavior plus a small Args block. Every word earns its place, and it is front-loaded with the core purpose. No fluff or redundancy.

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 tool with two required params and an output schema, the description covers the essential points: both parameter meanings and the existing-file constraint. It does not describe return values (output schema exists) but omits error scenarios (e.g., what happens if the file does not exist). Overall, it is sufficiently complete for the tool's low complexity.

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 has 0% description coverage, so the description must explain parameters. It does so well: 'path' is defined as relative to workspace root and must exist, while 'content' is described as text to append. This adds meaningful context beyond the bare schema, though it lacks examples or additional nuance.

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 ('Append text to the end of an existing file') with a specific verb and resource. It distinguishes itself from siblings like write_file (overwrite) and create_file (create new) by emphasizing 'existing file' and 'append'.

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 a clear usage context: file must already exist and text is added to the end. It implicitly tells the agent not to use this tool for creating or overwriting files, though it does not explicitly name alternative tools. This is clear guidance without exclusions.

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