Read lines from a Neovim buffer

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context beyond annotations: 'Opens the file if needed' discloses a potential side effect, and 'with line numbers' hints at the return format. This goes beyond what annotations provide, though it does not detail error handling or exact output structure.

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 three short sentences, front-loaded with the core purpose. Every sentence earns its place: the first states what it does, the second explains a key behavior (opening the file), and the third gives parameter guidance. There is no redundant or filler content.

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 simple read tool with strong annotations and complete schema, the description is largely sufficient. It covers the tool's core behavior, optional parameters, and a key side effect. While it could mention error cases or return format in more detail, the absence of an output schema and the simplicity of the operation make this a minor gap. The description is complete enough for an agent to select and invoke the tool correctly.

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 coverage is 100% with each parameter described. The description adds practical context by explaining that start_line and end_line are for 'read a slice of a large file,' which clarifies their purpose beyond the schema's individual descriptions. This reinforces the 1-based inclusive semantics and provides a use-case scenario, adding value over the schema alone.

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: 'Read a file through Neovim with line numbers.' It uses a specific verb (read) and resource (file/buffer), and distinguishes itself from sibling edit tools like nvim_edit_lines and nvim_insert_lines by emphasizing read-only behavior and line-numbered output. The title 'Read lines from a Neovim buffer' reinforces this.

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 implies usage by mentioning 'Use start_line and end_line to read a slice of a large file,' which gives context for when parameters are relevant. However, it does not explicitly contrast with alternatives such as nvim_open_file or nvim_edit_lines, nor does it state when not to use this tool. The usage guidance is present but implied rather than explicit.

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