Apply exact text replacements to a file in memory, validate expected match counts, then write atomically to prevent partial updates.
Apply one or more exact text replacements to a file in memory, validate expected match counts, then write once atomically.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| edits | Yes | ||
| expectedSha256 | No |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnly=false, destructive=true). The description adds meaningful details beyond annotations: edits are applied in memory, match counts are validated, and the write is atomic. It doesn't mention atomicity guarantees or failure behavior, but adds useful operational context.
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?
One efficient sentence that front-loads the core operation and includes key constraints. No wasted words.
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 mutation tool with 3 params and no output schema, the description covers the high-level flow but omits parameter details (e.g., expectedSha256, expected count semantics) and error handling. Annotations cover safety, but parameter-level guidance is missing.
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 0%, so the description could compensate but doesn't name any parameters. However, it does describe the core semantics of 'edits' and match validation. The nested 'expected' field is not explained. Baseline of 3 is appropriate given the schema does some structural work but lacks descriptions.
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 states a specific verb (apply text replacements), the target resource (a file), and the mechanics (in memory, atomic write). It clearly distinguishes fs_patch from fs_write (full write), fs_read, and fs_manage.
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 implies use for exact text replacements and mentions match validation, but doesn't explicitly say when to use fs_patch versus fs_write or fs_manage. No exclusions or prerequisites are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.