fast-filesystem-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'safely replace' and 'desktop-commander style', which hints at safety features, but doesn't elaborate on what makes it safe, error handling, or performance characteristics. The description adds some context but leaves important behavioral aspects unspecified.

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 at just 9 words, front-loading the core purpose ('Precise block editing') followed by key behavioral context. Every word earns its place with no wasted text or redundancy.

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 file editing tool with 8 parameters and no annotations or output schema, the description provides basic purpose but lacks important context about safety mechanisms, error conditions, or what distinguishes it from sibling editing tools. The 'desktop-commander style' reference is vague and doesn't sufficiently compensate for the missing behavioral details.

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?

The input schema has 100% description coverage, providing clear documentation for all 8 parameters. The description doesn't add any parameter-specific information beyond what's already in the schema descriptions, so it meets the baseline expectation without enhancing parameter understanding.

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's purpose: 'Precise block editing: safely replace exact matches'. It specifies the verb ('replace') and resource ('exact matches'), though it doesn't explicitly differentiate from sibling tools like 'fast_edit_blocks' or 'fast_safe_edit' beyond the 'desktop-commander style' reference.

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 multiple sibling editing tools (fast_edit_blocks, fast_edit_multiple_blocks, fast_safe_edit), there's no indication of when this specific 'block editing' approach is preferred or what distinguishes it from other editing operations.

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