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

While annotations already indicate readOnlyHint=false and destructiveHint=false, the description adds useful context by explaining that this is a paid (prepaid) operation that consumes funds and requires a funded session. It also mentions the sandbox receipt behavior without contradicting 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 information-dense, covering purpose, requirements, behavior, an optional flag, and the REST endpoint in a few sentences. The telegraphic style occasionally feels fragmented but overall is efficient and clear.

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 description gives a solid high-level overview and mentions the key flow (open, fund, query) and the sandbox option, but it omits details about the remaining parameters (query, k, delivery_receipt) and potential failure modes such as insufficient funds. Since there is no output schema or further annotation, these gaps reduce completeness.

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 low (only 2 of 5 parameters are described in the schema). The description partially compensates by explaining sandbox_receipt and implying delivery_receipt, but it leaves query, k, and delivery_receipt's exact role unexplained. Given the low schema coverage, more parameter clarification was needed.

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 purpose: to run a prepaid query against a funded data session and return attested hits plus a purchase receipt. It also distinguishes itself from free previews and other session operations, making its function unmistakable.

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?

It provides explicit guidance on when to use the tool: after opening and funding a data session, and it contrasts with the free data_preview option. It also notes the need for an API key, the sandbox_receipt parameter for testnet, and the REST endpoint, leaving no ambiguity about the required setup.

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