edit_file

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

Beyond the destructiveHint annotation, it reveals critical behavioral traits: returns a diff, preserves encoding and line endings, matching ignores whitespace/CRLF but requires interior spacing, and that a success with diff means the edit is on disk while failure changes nothing. It also details multi-match failure behavior and replaceAll semantics.

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?

Although long, every sentence provides necessary operational detail. It is front-loaded with purpose and usage priority, then flows logically through procedures, matching rules, and example. No filler or repetition that does not add value.

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 no output schema, the description clearly states the return is a unified diff. It covers expected behaviors for success, failure, dryRun, encoding, line endings, and edge cases like multiple matches. For a complex editing tool with 6 parameters, this description is exceptionally complete.

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 0%, and the description fully compensates. It explains each parameter: path, exactly one of edits or patch, dryRun default false, encoding auto, oldText matching constraints, replaceAll, similarity range, and provides a complete example. This is far beyond what the bare schema provides.

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 starts with a specific verb+resource: 'Edit one file with replacements or a unified diff.' It also distinguishes from siblings by explicitly stating 'PREFER THIS over read+write to modify a file,' making its purpose and differentiation crystal clear.

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 gives explicit when-to-use and when-not-to-use guidance. It says to prefer this over read+write, details the dryRun workflow for 'ask before edits' mode, and explains when to use similarity vs fixing oldText. It also warns against re-reading the file after successful edits.

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