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

With no annotations, the description carries the full burden. It discloses the entire output structure (winner, scores, conditions, dissenting links, tie-break reason, proof URLs), deterministic behavior ('same question returns the same answer'), and the refusal condition ('coverage: not_tested'). This is comprehensive and transparent for a read-only query tool.

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 long but every sentence earns its place: purpose, return value detail, determinism, refusal behavior, and routing guidance. It is front-loaded with the main purpose and flows logically. No fluff or redundancy.

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 complex (4 params, no output schema) and the description fully explains what the tool returns, including edge cases (refusal when not tested) and the conditions under which results hold. It also names a sibling for further raw data. This is complete for an agent to select and 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 schema already describes all 4 parameters with 100% coverage, so the baseline is 3. The description adds the 'Alternative: pass ranking + criterion explicitly' note, which is useful but does not significantly go below or above baseline. No additional syntax or format details are given beyond what the schema provides.

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 purpose: 'ANSWER a buyer question in ONE call: which tool is best at a specific capability, with proof.' It also differentiates from siblings by explicitly naming 'get_evidence' as an alternative for raw cells. The verb 'ANSWER' and the resource (buyer question about tool capability) are specific and unambiguous.

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 provides explicit usage guidance: 'Start HERE for any 'which tool is best at X' / 'A or B for X' question; use get_evidence for the raw cells behind it.' This gives both when to use and when not to use, naming a specific alternative. It also states the tool's honest refusal behavior when coverage is not tested.

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