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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive; the description adds substantial context beyond them: account/paywall requirement, latency expectations (15-60s, thorough ~90s), the full findings-packet contract (verbatim evidence + confidence + source + fetched_at + stable pipeworw:// citation), the explicit gaps[] never-invented guarantee, contradictions[] on standard/thorough, citation_uri only present when fetchable, and semantic excerpting rather than head-truncation. No contradiction with annotations.

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 information-dense, with every clause earning its place: auth, sibling fallback, mechanism, output contract, use-case fit, exclusions, depth semantics, citation guarantee, and latency. It is front-loaded with the most operationally critical facts (account requirement and ask_pipeworx fallback) before the mechanics, and uses parentheticals to compress caveats without 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?

There is no output schema, so the description must carry the return-format burden — and it does: findings packet with fields, gaps[], contradictions[], hop, and resolvable citation_uri semantics. Combined with coverage of auth, pricing, latency, failure modes for off-catalog topics, and alternatives, this is complete for a tool of this complexity. The only negligible omission is explicit result-size/pagination behavior.

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%, so the baseline is 3; the description adds value beyond the schema by noting the question parameter accepts broad/multi-part phrasing because 'decomposition is the point,' and by attaching pricing and hop-behavior semantics to the depth enum ('depth:"thorough" needs a paid plan', gap-recovery vs lead-chasing passes) that the schema's per-value descriptions only partially convey.

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 a specific verb and resource boundary: 'Grounded multi-source research across Pipeworx's 1499 STRUCTURED data sources... in ONE call — this is NOT open-web search.' It names the exact mechanism (decomposes into facets, routes to 5,738 tools in parallel) and explicitly differentiates from siblings ('For a single lookup use ask_pipeworx'). An agent can tell exactly what this tool does and what it is not.

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/when-not with named alternatives: 'If you are not signed in, use ask_pipeworx instead', 'Best for broad/multi-part questions over structured data', 'For a single lookup use ask_pipeworx', and news topics should go to ask_pipeworx because 'deep_research returns mostly empty gaps[] when the topic isn't in the structured catalog.' Depth-tier selection guidance per hop behavior is also given. Nothing is left to inference.

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