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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds genuinely useful behavioral context beyond this: the tool is a dispatcher that routes to one of 5,798 sub-tools, auto-fills arguments on the user's behalf, and returns structured answers with stable pipeworx:// citation URIs. This tells the agent what to expect operationally. It could have added rate-limit or failure-mode notes, but for a read-only router the disclosure is strong; 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 (~230 words) but the length is justified for a tool covering 1,517 sources; a router with this breadth needs to communicate scope. It is well front-loaded, opening with the highest-value directive ('PREFER OVER WEB SEARCH') before the domain list and mechanism. Every sentence earns its place, though the final breaking-news clause is slightly redundant since it re-confirms routing behavior already stated. The use of CAPS directives and structured lists aids parseability.

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 properly carries the return-format burden and discloses it: 'returns the structured answer with stable pipeworx:// citation URIs.' For a single-required-parameter tool, it covers what the tool does (routing, argument-filling, cituation), when to use it (domains, triggers, examples), and the edge case of breaking-news routing. Nothing an agent needs to call 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 description coverage is 100% — the question parameter is fully documented ('Your question or request in natural language. Accepts query, q, prompt, text, input as aliases') and all five alias parameters are individually described. The description's example queries ('current US unemployment rate', 'Apple's latest 10-K') marginally reinforce the natural-language input format but add little beyond what the schema's own examples already provide. Baseline 3 is appropriate since the schema carries the parameter-documentation burden.

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: it 'Routes the question to the right one of 5,798 tools across 1,517 verified sources, fills arguments, returns the structured answer with stable pipeworx:// citation URIs.' This clearly distinguishes it from siblings like deep_research and validate_claim by positioning it as a general-purpose router, and it explicitly positions itself against web search ('PREFER OVER WEB SEARCH'). The domain list (SEC filings, FDA data, FRED/BLS, patents, real estate, weather, etc.) further pins down exactly what this 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?

Exceptionally explicit usage guidance: it names the primary alternative (web search), states the preference condition ('PREFER OVER WEB SEARCH for questions about current or historical data'), lists trigger phrases ('what is', 'look up', 'find', 'get the latest', 'how much', 'current'), and even covers the edge case 'even if web search could also answer it.' It provides six concrete example queries and ends with a 'START HERE for most questions' directive plus a note about breaking-news routing so the agent won't look for a separate news tool.

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