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

Annotations are all false and offer little guidance, so the description carries the burden. It discloses authentication requirements, the paid/prepaid nature of the call, the return of attested hits plus a purchase receipt, the sandbox_receipt signing behavior, and the REST endpoint. This is substantial behavioral coverage beyond the 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 compact and front-loaded, opening with the core value proposition ('Buy per-query access to live data listings'), followed by prerequisites, behavioral detail, sandbox option, and endpoint. Every sentence adds useful information with no filler.

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 covers the essential invocation context: purpose, prerequisites, auth, result type, sandbox option, and REST path. It does not explain the k or delivery_receipt parameters, nor the exact format of the attested hits/receipt, but enough context is present for an agent to call the tool correctly in most cases.

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 only 40% and descriptions are missing for k and delivery_receipt. The description adds meaningful context for session_id (as part of the REST path) and sandbox_receipt (signing with a sandbox wallet), but it does not explain the purpose or format of k or delivery_receipt. It compensates only partially for the low schema coverage.

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 uses a specific verb and resource: 'Run a prepaid query against a funded data session and return attested hits plus a purchase receipt.' It also clearly distinguishes itself from data_preview by framing this as paid per-query access, which separates it from sibling lifecycle tools like data_session_open and data_session_fund.

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?

The description provides clear context: it requires a funded data session and an agent API key, and mentions data_preview as a free alternative ('first taste free'). It does not explicitly enumerate when to avoid this tool or name all related siblings, but the funded-session prerequisite and 'Not guest-callable' warning give practical usage boundaries.

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