config_explain

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds that this is a pre-edit diagnostic and lists the specific facts returned. It does not describe output shape or edge cases (e.g., behavior for files outside the project), which the schema hint about 'must be inside the project' only partially covers.

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?

Three short sentences, front-loaded with the purpose, then the usage trigger, then the parameter caveat. Every sentence carries distinct information with no repetition of schema 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?

With no output schema, the description takes on the burden of describing results and does so by enumerating the five questions it answers. Combined with full schema coverage and read-only annotations, an agent has everything needed to call it 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%, so baseline is 3; the description adds genuine conditional guidance for projectPath ('Set projectPath when the MCP server is not running from the project root'), which the schema does not express. It adds nothing extra for `file`, but that is already well described.

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?

States a specific verb ('Explain') and resource ('one project file') and enumerates exactly what the answer covers: ownership, source, current edit state, whether editing blocks `up`, and the recommended alternative. This is clearly distinguishable from siblings like config_verify and config_regenerate.

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?

Gives an explicit trigger: 'Run it before editing a file you did not write.' That is a concrete when-to-use condition. It does not name an alternative sibling tool or state when not to use it, so it stops short of a 5.

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