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

Annotations already declare readOnlyHint/openWorldHint/idempotentHint, but the description adds substantial context beyond them: account/paywall requirements, parallel facet decomposition, the findings packet contents, gaps[] with 'never invented', hop fields, fetchable citation_uri semantics, contradictions[] for standard/thorough, semantic excerpting, and latency expectations. 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?

Dense but every clause earns its place. The most critical operational constraint (account requirement and fallback to ask_pipeworx) is front-loaded. The description packs purpose, alternatives, behavior, return format, and latency into one well-structured block 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?

No output schema exists, so the description carries the burden of explaining return values — and it does thoroughly: findings packet fields, gaps[], contradictions[], hop, citation_uri, fetchability guarantee, and timing. Auth, fallback routing, and depth behavior are also covered. Nothing an agent needs to call or interpret this tool is missing.

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 baseline is 3. The description still adds practical meaning: depth:'thorough' requires a paid plan, standard vs thorough behavior differences ('re-angles unanswered gaps' vs 'chases the best leads'), and expected latency per depth. These nuances help an agent select the right enum value beyond the schema text.

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?

States a specific verb+resource: 'Grounded multi-source research across Pipeworx's 1497 STRUCTURED data sources... in ONE call'. Explicitly distinguishes itself from siblings: 'this is NOT open-web search' and contrasts with ask_pipeworx for single lookups. An agent can clearly tell what this tool does and what it does not do.

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 and when-not-to-use guidance: 'Best for broad/multi-part questions over structured data', 'For a single lookup use ask_pipeworx', 'For BREAKING or colloquial CURRENT-NEWS... prefer ask_pipeworx', and 'If you are not signed in, use ask_pipeworx instead'. Names the exact alternative tool and the conditions that route to it.

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