Index a repository

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

With no annotations, the description carries the full burden. It adds meaningful behavioral details: it skips unchanged files via content hash, supports specific languages, and persists to Neo4j. However, it does not disclose whether re-indexing replaces or merges existing graph data, whether Neo4j needs to be running, or any prerequisites. For a mutation tool, these are notable gaps.

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 two sentences, front-loaded with the core action, then usage and supported languages. Every sentence serves a purpose with no filler. It is appropriately sized for the tool's scope.

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 moderately complex (builds a code graph, has re-indexing behavior), and there is no output schema or annotations. The description covers the main action and re-indexing but omits operational details like whether existing graph data is updated or destroyed, whether Neo4j must be pre-configured, and what the tool returns. These are meaningful gaps for an AI agent deciding to invoke it.

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 the baseline is 3. The description adds semantic value beyond the schema by explaining the content-hash skipping behavior, which gives context to the 'force' parameter (re-parse ignoring hashes). It also frames the 'repo' identifier through 'Run this once per project,' even though the schema already explains defaults.

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: 'Parse a repository and build its code graph in Neo4j.' It uses a specific verb ('build') and resource ('code graph in Neo4j'), and distinguishes itself from sibling tools that are all query/analysis tools (e.g., find_symbol, hotspots) by being the indexing/setup step. Supported languages are also listed, adding clarity.

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 timing guidance: 'Run this once per project, and again after significant changes.' It also explains the cost benefit ('unchanged files are skipped by content hash, so re-indexing is cheap'). While it doesn't explicitly mention when not to use it or alternatives, the context of sibling tools implies this is for initial setup, making the usage context clear.

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