stats

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

With no annotations provided, the description must carry the behavioral disclosure. It indicates a read operation via 'Return', implying no side effects. However, it does not explicitly state that it is read-only, nor does it mention any requirements or limitations (e.g., behavior with empty index). This is adequate for a simple stats tool but leaves some behavioral details implicit.

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 a single, dense sentence with no redundant words. It front-loads the purpose and lists the specific data points returned, making it highly scannable.

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 the low complexity (no params, no annotations, no output schema), the description adequately conveys the tool's function and return contents. It does not explicitly mention the scope (e.g., current index or project), but this is likely implied by the tool's name and context. Minor gap, but not critical.

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 tool has zero parameters, and the schema is empty (100% coverage). The baseline for 0-parameter tools is 4, and the description does not need to add parameter details. It correctly focuses on the output rather than inputs.

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 the specific verb 'Return' and the resource 'index stats', and enumerates the exact contents (file count, symbol count, per-language breakdown). This clearly distinguishes it from siblings like list_languages or search_symbols, which serve different purposes.

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 no guidance on when to use this tool versus alternatives. It does not mention any prerequisites (e.g., an index must exist) or contrast with list_languages, which also provides language-related information. The agent is left to infer the appropriate context.

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