fs__edit_file

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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It conveys that edits are line-based, require exact matches, and return a git-style diff. However, it does not specify whether the operation is atomic, what happens if oldText is not found, or the file must exist, leaving gaps in expected behavior.

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: three sentences that first state the main function, then detail the mechanism and output, and finally note a constraint. Every sentence adds value with no redundancy or unnecessary information.

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 the tool's moderate complexity (3 parameters, no output schema), the description covers the key aspects: what it does, how it works, what it returns, and a constraint. It lacks detail on edge cases (e.g., matching failure, file type requirements) but provides sufficient context for typical use.

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 coverage is 33% (only dryRun and inner fields have descriptions). The description adds context that edits are line-based and exact, but does not elaborate on the 'path' parameter or provide format constraints. The schema's own description of oldText ('must match exactly') is sufficient, but the overall parameter semantics are minimally reinforced.

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 tool makes 'line-based edits to a text file,' specifying the verb (edit) and resource (text file). It distinguishes from siblings like fs__write_file, which overwrites entire files, by emphasizing line-level changes and exact replacement.

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 explicit guidance on when to use this tool versus alternatives. It mentions a constraint ('only works within allowed directories') but lacks a direct comparison to sibling tools like fs__write_file or suggestions for when line editing is preferred.

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