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

Beyond the readOnlyHint/openWorldHint annotations, it discloses runtime, the async job-id pattern, webhook-driven delivery context, the $5 USDC x402 price, and the conditional non-charge policy including the subtlety that async checks the core source before queueing and charging. That is exactly the cost/side-effect context 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?

One dense paragraph that front-loads what the tool produces before moving to timing, async, billing, and refund. It is long but nearly every clause carries distinct information; only the repeated async caveat is slightly redundant.

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, yet the description fully characterizes the deliverable, its runtime, delivery modes, and the payment/refund model. An agent has everything required to decide to call it, choose async, and anticipate the charge.

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?

With 75% schema coverage the schema already documents pdf, async, and webhook_url, so the baseline is 3. The description earns above baseline by explaining what async actually changes (job id returned now, report later) and by framing topic as 'any market', plus confirming a PDF is part of the output.

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 ('market research brief on any market') and enumerates the deliverable contents (market size with sources and ranges, segments, players, business models, drivers, trends, risks, entry opportunities, attractiveness score, PDF). This clearly separates it from siblings like report_company, report_competitors, and research.

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 concrete operating guidance: 'async=true recommended', the 60-150 s runtime, and the billing/refund condition ('If too few sources answer you are not charged'). It does not explicitly name a sibling as the alternative for narrower asks (e.g. report_company), so it falls short of a 5.

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