get_buf_diagnostics

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

Declares read-only nature, precondition (buffer must be open), and describes return format including severity levels. Fully transparent without annotation reliance.

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?

Concise 5-sentence description with front-loaded purpose. Every sentence adds value: purpose, read-only, parameter semantics, usage guidelines, return format.

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?

Covers all necessary aspects for a simple tool: purpose, usage, parameter semantics, return format with severity values, error condition. No gaps despite no output schema.

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?

Adds crucial context beyond schema: 'file path relative to Neovim's cwd (as shown in `get_state` buffers). The buffer must already be open; returns an error otherwise.' Schema has 0% coverage, so description compensates fully.

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?

Description clearly states it gets LSP diagnostics for a single Neovim buffer, distinguishing it from the sibling 'get_all_diagnostics' by specifying 'single' vs 'project-wide'. Verb and resource are explicit.

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?

Explicitly provides guidance: 'Use this when you need diagnostics for one specific file. Use `get_all_diagnostics` instead for a project-wide overview.' Also states buffer must be open.

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