Index / refresh the repository

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

With no annotations provided, the description carries the full burden. It discloses that only files with changed mtimes are re-parsed, that it honors a specific config file (.slimdex.json) with listed options, and that it reports config problems instead of ignoring them. This is substantial behavioral disclosure, though it does not mention permissions or output formats.

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 three sentences, each earning its place: first defines the tool's core action, second gives usage guidance, third explains configuration handling. It is front-loaded with the main purpose and contains no unnecessary 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?

For a single-parameter tool with no output schema, the description covers purpose, usage context, and configuration behavior. It also implies the tool's role in relation to search tools ('before trusting a search'), making it complete enough for an agent to invoke 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?

The sole parameter `force` is fully documented in the schema with description 'Ignore cache and reparse everything.' The tool description does not add additional parameter detail, but schema coverage is 100%, so the baseline of 3 applies. The description's mention of incremental behavior implicitly contrasts with the force param, adding minor context.

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 that it 'Builds or refreshes the persistent code index (symbols + imports)', using a specific verb and resource. This distinguishes it from sibling tools like search_code or find_definition, which consume the index rather than build it.

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 explicitly advises to 're-run it liberally, like git fetch, before trusting a search', giving clear when-to-use guidance. It doesn't list explicit when-not-to-use conditions, but the analogy to git fetch and the reference to search readiness provides strong contextual usage guidance.

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