index_repository

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

With no annotations provided, the description carries the full burden of behavior disclosure, and it does reasonably well: it declares persistence behavior ('on-disk cache for fast re-runs'), signals re-indexing with refresh=true, and describes the data that is extracted. It stops at details like what the tool returns or whether it is non-destructive, but the core behavioral traits are covered.

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 sentences, no filler: the first defines what it does, the second gives the call-order rule applied, and the third explains caching. Important behavioral information is front-loaded, and every clause adds value.

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 a simple two-parameter schema with no output schema and no annotations, the description is close to complete: it asserts when to call it for the first time, when to re-run with refresh, what the internal behavior is (dependency graph building and caching), and what gets updated. It could specify what happens after indexing or what success looks like, but it is complete enough for this kind of setup tool.

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 0%, so the description must compensate. It does explain refresh past the schema by tying it to re-running after file changes. However, repo_root is never mentioned or defined; an agent can infer it is the repository path, but the uncertainty is left to guesswork. Since at least one parameter is semantically enriched and the other is left implicit, this is adequate but not strong.

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 action and resource: 'index (or re-index) a repository' and enumerates what it extracts — files, symbols, imports, and a reverse dependency graph. It reads as an explicit foundation step, and the siblings (get_repo_overview, search_code, get_dependencies) are clearly different read/query tools rather than indexing tools.

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 says 'Call this first, and again with refresh=true after significant file changes.' This is direct when-to-use guidance, making the invocation very and rerun conditions clear. It does not explicitly contrast with the sibling tools, but the relationship is strongly implied: this is the preliminary indexing step before querying with the get_* siblings.

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