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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), but the description goes well beyond them: account/paid-plan requirements, expected latency (15–60s, up to ~90s), the depth-specific iteration behavior (gap recovery vs. lead chasing), that gaps[] are never invented, that citations are only present when resolvable, and that large records are semantically excerpted rather than head-truncated. This is rich operational context.

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?

Front-loaded with the gating constraint (ACCOUNT REQUIRED) and then organized around capability, output, best-fit cases, and timing. It is dense and mentions ask_pipeworx routing three times, but each mention serves a distinct condition (not signed in, single lookup, breaking news), so the length is largely earned rather than padded.

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 and 9 parameters, the description carries the full burden and does so: it enumerates the return packet fields (evidence, confidence, source, fetched_at, citation, gaps[], hop, contradictions[]), the auth/tier prerequisite, and latency expectations. Nothing an agent needs to call and interpret this tool correctly 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 the baseline is 3; the description still adds value by stating that depth:'thorough' requires a paid plan — a constraint absent from the schema — and by clarifying that standard/thorough add a contradictions[] scan. The rest of the depth semantics largely restate the schema, keeping it out of 5 territory.

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 and resource ('Grounded multi-source research across ... 1847 STRUCTURED data sources ... in ONE call') and immediately distinguishes itself from non-siblings ('this is NOT open-web search') and from the family alternative ask_pipeworx. An agent can tell exactly what this does without opening the schema.

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?

Explicit when-to-use ('Best for broad/multi-part questions over structured data') and when-not-to-use, naming the alternative for each condition: single lookup → ask_pipeworx, breaking/colloquial current-news → ask_pipeworx (with the reason: deep_research returns empty gaps[] for out-of-catalog topics). Depth-tier guidance 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.