lsp_format_preview

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

With no annotations, the description discloses non-destructive behavior ('without writing any files') and the output format (unified diff). This gives the agent a clear safety profile, though it omits details like server capabilities required or error handling.

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?

A single sentence (12 words) that is front-loaded with purpose and outcome. Every word contributes value; no redundancy or filler.

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?

The description is minimal but covers the essential preview behavior. It lacks prerequisites (e.g., file must be in workspace), details on diff format, and error scenarios. For a tool with no output schema and moderate complexity, it is adequate but not thorough.

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 for all four parameters (filePath, tabSize, includeDiff, insertSpaces). The tool description adds little beyond what the schema already provides, only contextualizing that the output is a diff, which relates to includeDiff.

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: 'Preview formatting changes for a file.' It specifies the key behavior ('Returns a unified diff without writing any files'), distinguishing it from other LSP tools that may write changes or preview ranges.

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 does not explicitly guide when to use this tool over alternatives like lsp_range_format_preview or lsp_workspace_edit_preview. Usage context is implied by the name and preview behavior, but no when-not or alternative hints are provided.

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