index_repo

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 states the action but does not disclose side effects, idempotency, persistence, required permissions, or whether the operation is synchronous. The mutation of the repository index is implied but not elaborated.

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 and front-loaded. The first sentence states the purpose, and the second documents the parameter. No unnecessary words or repetition.

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?

The tool is simple (one parameter) and has an output schema, so return value documentation is not necessary. However, the description lacks guidance on when to use the tool relative to siblings, does not explain the indexing behavior (e.g., overwriting vs incremental), and omits any potential side effects or requirements. It is minimally viable but leaves gaps.

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 provides only the parameter name and type, but the description adds meaningful context: 'absolute path to the repo root to index.' This clarifies the expected format and purpose of the path parameter, compensating 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's function with a specific verb ('ingest') and resource ('a repository'), and specifies the output ('build the hybrid (dense + BM25) index'). This distinguishes it from sibling tools like search_code, which are for search operations.

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 that indexing should happen before searching (given the sibling tool search_code), but it does not explicitly state when to use this tool versus alternatives. There is no direct guidance on prerequisites or ordering.

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