locate_option

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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns files declaring and defining an option with contributed values, which is the primary behavior. It does not mention side effects (none expected) or permissions, but given the read-only nature implied (locating, not modifying), this is adequate.

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 extremely concise: two sentences and one parenthetical example. It is front-loaded with the main purpose and provides an example immediately. Every sentence adds value, with no wasted words.

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?

Given the tool has 3 parameters, 1 required, and an output schema exists, the description covers the 'attr' parameter and return values implicitly. However, it omits 'mode' and 'flake_uri', which are important for context (e.g., NixOS vs Home Manager mode). The Home Manager mention partially addresses this but not fully.

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 0%, so the description must add meaning. It only explains the 'attr' parameter with an example and a special Home Manager syntax. The 'mode' and 'flake_uri' parameters are not mentioned, leaving their semantics undocumented. Thus, it only partially compensates for the lack of schema descriptions.

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 locates where a configuration option is set, listing files and contributed values. It uses a specific verb ('locate') and resource ('option'), and the example attr='services.openssh.enable' clarifies the purpose. While it distinguishes itself from siblings like 'build' or 'check', it does not explicitly compare, so it's very clear but not perfect.

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 for discovery and editing ('bridge from mcp-nixos discovery to editing the right file') and provides a special case for Home Manager. However, it does not explicitly state when not to use this tool versus alternatives like eval_config or inspect_flake, nor does it mention prerequisites or error conditions.

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