fast-filesystem-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool edits files but doesn't mention critical details like whether edits are atomic, if there's error handling for failed edits, permissions required, or how backups work. For a mutation tool with zero annotation coverage, this leaves significant gaps in understanding its 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 a single, efficient sentence that directly states the tool's function without unnecessary words. It's front-loaded with the core action, making it easy to grasp quickly. Every word earns its place, achieving optimal conciseness.

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 complexity of editing multiple file parts, lack of annotations, and no output schema, the description is incomplete. It doesn't address key aspects like error handling, edit atomicity, or return values, leaving the agent with insufficient context to use the tool effectively in real-world scenarios.

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%, so the input schema fully documents the parameters (path, edits, backup). The description adds no additional meaning beyond implying 'multiple parts' relates to the 'edits' array, but it doesn't clarify semantics like edit ordering or conflicts. With high schema coverage, 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 clearly states the action ('edits') and resource ('multiple parts of a file'), making the purpose understandable. However, it doesn't explicitly differentiate from similar siblings like 'fast_edit_block' or 'fast_edit_blocks', which likely handle single or multiple edits differently, leaving some ambiguity about when to choose this specific tool.

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 provides no guidance on when to use this tool versus alternatives. With siblings like 'fast_edit_block', 'fast_edit_blocks', and 'fast_safe_edit', it's unclear what distinguishes this tool—whether it's for efficiency, atomicity, or specific edit types. No context or exclusions are mentioned.

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