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

Goes well beyond the readOnlyHint annotation by disclosing the paid-access model: $0.25 USDC per call, Solana mainnet settlement, and the challenge/response handshake. These are exactly the operational facts an agent needs and are not in the annotations or schema.

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?

Two dense sentences, front-loading what the brief contains and then the payment mechanics. No filler and nothing buried.

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 return-shape burden and does so ('total + breakdown, insights, risks'), plus the full payment flow. An agent has everything needed to call it correctly.

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%, and the schema already explains topic selection and the omit-then-resubmit pattern for payment_signature. The description restates the payment flow but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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 resource and its contents: a 'structured market brief' with 'total + breakdown, insights, risks.' An agent knows exactly what it gets. It does not, however, differentiate itself from siblings like get_metric or get_price, so it stops short of a 5.

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 explicit two-step usage: first call without payment_signature yields the challenge, then pay and re-call with the signature. That is clear procedural guidance. It omits when to prefer this brief over sibling tools like get_metric or verify_claim.

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