fast-filesystem-mcp

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fast_edit_multiple_blocks

Edit multiple sections of a file in one operation. Specify old text to find, new text to replace, line numbers, and mode (replace, insert before, insert after, delete line). Optionally create a backup.

Instructions

Edits multiple parts of a file at once

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "path": "<path>",
      "edits": "<edits>"
    },
    "name": "fast_edit_multiple_blocks"
  }
}

Input Schema

Name	Required	Description
`path`	Yes	Path of the file to edit
`edits`	Yes	List of edit operations
`backup`	No	Create a backup

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv1.0.0Jan 3, 2026
- changedInput schema / properties / backup / description
```
Previous value: -"백업 생성"New value: +"Create a backup"
```
- changedInput schema / properties / edits / description
```
Previous value: -"편집 작업 목록"New value: +"List of edit operations"
```
- changedInput schema / properties / edits / items / properties / line_number / description
```
Previous value: -"라인 번호"New value: +"Line number"
```
- changedInput schema / properties / edits / items / properties / new_text / description
```
Previous value: -"새로운 텍스트"New value: +"The new text"
```
- changedInput schema / properties / edits / items / properties / old_text / description
```
Previous value: -"찾을 기존 텍스트"New value: +"Existing text to find"
```
- changedInput schema / properties / path / description
```
Previous value: -"편집할 파일 경로"New value: +"Path of the file to edit"
```
First observedAug 22, 2025

TDQS

C2.7/5.0

Behavior2/5

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

No annotations are provided, so the description carries full burden. It only states 'edits multiple parts' but doesn't disclose mutation behavior, error handling, order of edits, or backup creation (though backup param exists in schema).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness2/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Extremely concise (6 words) but under-informative for a tool with 3 parameters and no annotations. Could include brief details about edit operations or usage without becoming verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given tool complexity (3 parameters, no output schema, no annotations), the description is incomplete. It fails to explain atomicity, order of edits, conflict resolution, or return value.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Input schema has 100% description coverage, so parameters are adequately documented. The description adds no additional meaning beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool edits multiple parts of a file at once, distinguishing from sibling tools that edit single blocks (fast_edit_block) or perform other file operations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like fast_edit_block or fast_safe_edit. No context about prerequisites or limitations.

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