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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false, and the description adds substantial behavior beyond them: the exact success return shape ({answer, evidence, confidence, source, fetched_at, refusal_reason:null}), the full enumerated refusal contract with five refusal_reason values, the extraction-only guarantee, the open-world routing behavior (5,908 tools / 1540 sources), and the cost tradeoff ('Costs one extra LLM call'). No contradiction with annotations; the openWorldHint is corroborated by the routing description.

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: core differentiator front-loaded, then routing behavior, then success/refusal return contracts, then usage guidance, then cost tradeoff. The structured parallelism between success ({answer, evidence,...}) and refusal ({answer:null, refusal_reason}) makes it scannable. Nothing is redundant or filler.

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?

With no output schema present, the description carries the full burden of explaining return values — and it does so exhaustively, covering success shape, refusal shape, and every refusal reason. Given the tool's complexity (routing, evidence extraction, refusal modes, cost), nothing an agent needs to invoke it correctly is missing. Sibling differentiation is fully handled via the ask_pipeworx comparison.

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 description coverage is 100%, so the baseline is 3 — the schema fully documents 'question' and its five aliases. The description adds meaning beyond the schema by explaining the parameter's role: the question drives tool selection across 5,908 tools and gets used to 'fill arguments' in the routed tool, which orients the agent on how to phrase input. It stops short of giving question-format quality tips, but with full schema coverage that gap is minor.

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 opens with a specific, differentiating statement: 'Hallucination-resistant answer mode for high-stakes reads.' It names the resource (Pipeworx grounded answering) and explicitly contrasts with the sibling ask_pipeworx ('Same routing as ask_pipeworx... then EXTRACTS the answer using ONLY what the tool result contains'). An agent can immediately tell this apart from ask_pipeworx, ask_pipeworx_beta, deep_research, and validate_claim.

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?

Provides explicit when-to-use guidance: 'Use whenever an answer will be quoted, cited, or acted on, and the agent must not invent facts,' with concrete domain examples (financial verdicts, legal claims, medical lookups, public statements). It also gives the exclusion: 'prefer ask_pipeworx for casual lookups,' naming the alternative tool directly. This is textbook usage routing.

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