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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true) by disclosing the async contract: a job id and due time returned immediately, report ready within 24 hours, polling free at GET /v1/jobs/:id. It also documents payment rails, per-call pricing, and failure semantics — 'failed calls aren't charged when you pay per call with x402' and credit return for pack credits — which is exactly the risk information an agent needs before spending money.

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-loads the deliverable and its word count before the delivery mechanics, then the money terms. Every clause carries information, though the billing paragraph is dense and restates the $9.00 price already in the title, which is slight 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?

This is a paid, asynchronous, open-world tool with no output schema, and the description covers everything an agent needs: what comes back immediately (job id, due time), how to retrieve the result, the latency bound, the cost, and the refund behavior on failure. Nothing material is left to inference for a paid call.

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% with only two parameters (topic, focus), both already documented in the schema, so the description carries little extra burden. It does convey that the tool produces operator-checked cited research, but adds no syntax, formatting, or scoping guidance for topic/focus beyond the schema text — baseline 3 is appropriate.

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 deliverable (in-depth research report with cited sources) plus concrete output shape: ~1,500 words, executive summary, key findings, and at least 8 cited public sources. The phrase 'for decisions that need more than a quick note' implicitly separates it from the lighter `brief` sibling, so an agent can route without opening either 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?

Gives a clear selection criterion ('decisions that need more than a quick note') and explains the delivery path via GET /v1/jobs/:id, pointing at the polling flow. It never explicitly names the alternative tools (`brief`, `brief_status`) or states when not to use this tool, so the routing signal is implied rather than spelled out.

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