Run an Ex command

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

Annotations declare readOnlyHint=false and destructiveHint=true, so the agent already knows this can mutate state. The description adds that it returns output, which is useful, but does not elaborate on side effects or risks beyond what annotations imply. It neither contradicts annotations nor adds deep 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 exactly two sentences, no wasted words. The first sentence states purpose with examples, the second provides usage context. Every sentence earns its place.

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?

With a single parameter, full schema coverage, no output schema required, and annotations covering safety, the description is sufficient. It explains what it does, gives examples, mentions output return, and states the intended use case for plugins.

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 provides a clear description of the 'command' parameter (Ex command without leading colon). The description adds value through concrete examples ('Telescope find_files', 'Git blame') that illustrate expected input, enhancing understanding beyond 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 runs a Neovim Ex command, with concrete examples like 'Telescope find_files' and 'Git blame', and explicitly distinguishes this from other sibling tools by focusing on Ex commands and plugin driving.

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 gives clear usage context: 'Use this to drive installed plugins.' This implies when to use it (invoking plugin commands) but does not explicitly name alternatives or exclusions, such as using nvim_exec_lua for Lua code, leaving a small gap.

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