corpus_stats

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

No annotations exist, so the description must convey behavior. It discloses that the tool evidences 'silence' or absence, which is a non-obvious behavioral trait. It implies read-only operation by describing corpus contents. However, it doesn't detail output format or potential side effects, though with 0 params, that's a minor gap.

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?

Two sentences with zero wasted words. The key information is front-loaded in the first sentence, and the second provides actionable usage guidance.

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?

Despite lacking an output schema, the description adequately describes the tool's role and when to use it. It's simple (0 params), so the description is nearly complete. The only missing piece is what the actual output looks like, but for a stats tool, the purpose is self-explanatory.

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?

With zero parameters, the schema already fully covers the input contract. Per baseline for 0-param tools, this is a 4. The description adds no parameter-specific detail, but none is needed.

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 uses a specific phrase 'What this corpus contains and, more importantly, what it does NOT' to convey it reports corpus contents and gaps. It distinguishes from search_claims and coverage_for by focusing on corpus-level stats rather than searching or coverage checking. However, it lacks an explicit verb like 'returns' or 'calculates', slightly reducing 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?

Explicitly states when to call: 'when you are about to say the corpus has no answer', framing it as a verification tool for absence claims. This provides clear contextual guidance and implies alternatives (search_claims for searching, coverage_for for coverage) without naming them.

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