append_file

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

No annotations are provided, so the description carries full responsibility. It discloses the auto-creation behavior, but omits other important traits such as whether parent directories are created, encoding handling, error conditions (e.g., path is a directory), or output format. The presence of an output schema is indicated but not described.

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 a single sentence of 10 words, highly concise and front-loaded. Every word contributes meaning without 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?

Given that an output schema exists (but is not shown), the description does not need to document return values. However, in the context of many sibling file tools, the description lacks details like whether content is appended with a newline, how creation handles directory structure, and any side effects. It is minimally complete for a straightforward append operation.

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%, with minimal descriptions ('Destination path.', 'Text to append.'). The tool's description adds no further semantic detail about the parameters beyond what the schema already provides, so a baseline score 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 uses a specific verb ('append') and resource ('a file'), and adds the behavior of creating the file if needed. This clearly distinguishes it from sibling tools like 'write_file' (overwrite) and 'replace_in_file' (pattern-based modification).

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 does not provide any guidance on when to use this tool versus alternatives. While the name and sibling list suggest the difference, there is no explicit statement of when to choose 'append_file' over 'write_file' or 'replace_in_file'.

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