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

With no positive annotation hints, the description carries the behavioral burden and does disclose important traits: per-query billing at 0.01 USDC, a 20-query session cap, and the need for a funded session. It does not detail receipt-signing side effects or error outcomes, but the disclosed cost and sequencing are meaningful.

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 with purpose, then pricing/limits, then workflow. The 'Listing: scibreak...' detail is somewhat specific but concise and relevant to the paid-access context. No major redundancy in the main description.

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?

The workflow and pricing are covered, but the tool still requires five parameters and has no output schema. The description leaves key parameter semantics unexplained, especially 'query' and 'k', and does not describe response behavior. An agent would likely need additional information to invoke 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?

Only 40% of parameters have schema descriptions, and the tool description does not compensate. It never explains the semantics of 'query' or 'k', nor does it clarify 'delivery_receipt' or 'sandbox_receipt' beyond what the schema already states. The central query parameter is left under-specified.

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 clearly states the tool's action: 'Buy per-query access to live data listings' and 'Run a prepaid query against a funded data session.' It also differentiates itself from data_preview by calling it a free first taste, and positions itself correctly among sibling sequence tools.

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 explicitly names the workflow: 'Sequence: data_session_open → data_session_fund → data_session_query.' It also tells the agent that data_preview is the free alternative for an initial taste, giving clear when-to-use vs. alternative guidance.

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