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

Annotations already declare readOnly/openWorld/idempotent, and the description adds substantial context beyond them: account/paid-plan requirements, parallel decomposition across 5,798 tools, the findings packet structure (verbatim evidence, confidence, source, fetched_at, citation_uri), the gaps[] honesty guarantee ('never invented'), contradictions[] on standard/thorough, semantic excerpting rather than head-truncation, and latency expectations (15-60s, up to ~90s for thorough). 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 (~280 words) but densely packed with distinct value: critical routing info (account required, alternative tool) is front-loaded, followed by scope, behavior, return format, and latency. Minor deduction for re-explaining depth semantics that the input schema already covers in its enum descriptions — some redundancy, though defensible given the tool's complexity.

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, the description carries the full burden of explaining return values, and it does thoroughly: findings packet fields, gaps[], contradictions[], hop field, citation_uri resolvability, and excerpting behavior. It also covers prerequisites (account/tier), the not-signed-in fallback, latency, and error semantics (gaps for unanswered facets). Little an agent needs to invoke or evaluate results 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% and the schema's depth enum is already well-documented (hop counts, gap-recovery, contradictions scan). The description adds value beyond the schema by tying depth to cost ('thorough' needs a paid plan), explaining hop mechanics in prose ('re-angles unanswered gaps', 'chases the best leads'), and framing the latency difference per depth. Slightly redundant with the schema, hence not a 5.

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 (decomposes, routes, returns) and resource ('1517 STRUCTURED data sources' across SEC, FRED/BLS, FDA, USPTO, etc.), and explicitly differentiates from siblings: 'this is NOT open-web search' and 'For a single lookup use ask_pipeworx.' Concrete examples ('compare X and Y's regulatory + financial exposure') further pin down what the tool is for.

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 ('Best for broad/multi-part questions over structured data'), when-not-to-use ('For a single lookup use ask_pipeworx'), and a named alternative with a concrete condition ('If you are not signed in, use ask_pipeworx instead — it works on every tier'). Even the depth choice is tied to use case (multi-step questions resolve in one call with standard/thorough).

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