Save a buffer

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

The description discloses that 'BufWritePre autocommands run, so formatters and linters fire,' which goes beyond the annotations' readOnly/idempotent/destructive hints. This warns the agent about potential side effects like automatic formatting, which is valuable behavioral 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?

The description is two sentences with the core action front-loaded and the usage context immediately after. Every sentence earns its place without unnecessary wording.

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 single-parameter save tool with rich annotations, the description covers the purpose, usage timing, and behavioral side effects. No output schema is needed, and the tool is simple enough that no further context is required.

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 schema already covers the single 'path' parameter with a 'File path' description, so the baseline is 3. The tool description does not add further semantic detail about the parameter beyond what the schema provides.

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 opens with 'Write a buffer to disk,' a specific verb+resource that clearly states the tool's function. This distinguishes it from sibling tools like nvim_open_file, nvim_read_file, and nvim_edit_lines, which perform different operations.

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 instruction 'Use this after edits made with save set to false' provides concrete guidance on when to invoke this tool. While it doesn't explicitly name alternative tools, the context of deferred saving clearly implies this is the intended follow-up to edit operations.

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