Index Repositories

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

The annotation readOnlyHint is false, and the description aligns with that by stating 'Without dryRun this mutates the persistent local catalog, so it is not a pure read.' It also discloses that dryRun is read-only. This goes beyond the annotation by specifying the exact mutation target (catalog) and the read-only mode. No contradictions detected.

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 concise—three sentences total. It front-loads the primary purpose, then covers key options (discover, dryRun) and a critical caveat about mutation. Every sentence carries useful information with no filler. Excellent structure.

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 tool with 7 parameters (none required), no output schema, and no nested objects, the description covers the essential operational modes: discovery and dryRun. It explains the mutation side effect and the replacement of an older tool. It does not describe the return value or the format of the generated indexes, but since there is no output schema and the description is already focused on invocation behavior, this is adequate. A 4 is appropriate.

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 description coverage is 100%, so the schema already documents all parameters. The description adds value by explaining the functional interplay of dryRun and discover, e.g., 'Pass discover:true to find repository roots under the given paths first' and 'Pass dryRun:true to discover and report without writing any indexes.' This is beyond the individual parameter descriptions, providing usage semantics that help the agent decide how to set them. Baseline is 3 due to high coverage, but the added context justifies a 4.

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 states a clear purpose: 'Index local repositories: generate per-user external indexes and add them to the local catalog.' It identifies the primary action and resource. It does not explicitly differentiate from sibling tools like repo_inspect or repo_map, but the verb 'index' and the mention of generating indexes is sufficiently distinct. A 4 is warranted because while the purpose is clear, it lacks direct sibling differentiation.

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 explicit guidance on using the dryRun parameter: 'Pass dryRun:true to discover and report without writing any indexes or catalog (read-only)' and explains that without dryRun it mutates the persistent catalog. It also mentions that dryRun replaces the old repo_discover tool. However, it does not compare this tool to alternatives like repo_inspect or repo_map, so the guidance is mostly about parameter usage rather than when to choose this tool over others. This is a solid 4.

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