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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, destructiveHint=false, and the description is fully consistent with them. It adds substantial behavior beyond annotations: the tool refuses rather than fabricates when data doesn't answer, enumerates five refusal_reason values, returns a verbatim evidence quote, and carries a one-extra-LLM-call cost. The 'EXTRACTS using ONLY what the tool result contains' constraint is a significant disclosed behavioral trait.

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?

Six sentences, each earning its place: purpose, routing mechanism, success return shape, refusal return shape, usage guidance, and cost tradeoff. The differentiator is front-loaded in the first sentence, and the return-shape details are necessary because no output schema exists. There is no fluff or repetition of annotation content.

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?

For a grounded Q&A tool with one well-documented parameter, the description covers everything an agent needs: the return contract (success and refusal), all refusal reasons, the evidence requirement, when to use, and the cost/alternative. Since no output schema exists, the inline return-shape disclosure is essential and is fully supplied.

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% — the lone question parameter and its five aliases (q, query, prompt, text, input) are fully documented in the schema. The description adds no parameter-specific format guidance, but none is needed since the schema carries the full burden. Per the baseline rule for full schema coverage, 3 is appropriate.

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 opening phrase 'Hallucination-resistant answer mode for high-stakes reads' names a specific mode, verb, and resource. It further distinguishes itself from ask_pipeworx by noting it uses the same routing but then EXTRACTS the answer using ONLY what the tool result contains. An agent can tell it apart from ask_pipeworx and ask_pipeworx_beta without inspecting schemas.

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 explicitly states when to use: 'Use whenever an answer will be quoted, cited, or acted on, and the agent must not invent facts,' with concrete domains (financial verdicts, legal claims, medical lookups, public statements). It also gives the exclusion — 'prefer ask_pipeworx for casual lookups' — backed by the one-extra-LLM-call cost rationale. This is explicit when-to-use, when-not-to, and which alternative to pick.

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