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

Annotations already indicate this is not read-only, not idempotent, and not destructive. The description adds valuable behavioral context beyond annotations: each query costs 0.01 USDC and is capped at 20 queries per session. It does not disclose failure behavior or what happens when funds run out, but the cost and session limits are meaningful transparency additions.

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 three concise sentences with no filler. It front-loads the core purpose, includes pricing and session limits, and closes with the required sequence. Every sentence earns its place.

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 tool has no output schema and moderate parameter complexity, so the description carries a heavy burden. It covers the session lifecycle, pricing, and max query cap, which is enough for an agent to understand the basic call route. However, it does not describe the expected return value, query formatting, or the role of k/delivery_receipt, leaving clear gaps for a paid mutation-style tool.

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 only 40%, with session_id and sandbox_receipt documented in the schema, but the required query parameter and optional k and delivery_receipt parameters lack semantic guidance. The description mentions the listing and per-query pricing but does not explain what a valid query looks like, what k controls, or how delivery_receipt should be used, so it fails to compensate for the schema gaps.

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 identifies the tool as a paid per-query data access operation and clearly positions it within the data_session lifecycle, mentioning the ghsawatch listing. It is less crisp than an explicit 'run a query against a funded session' statement, and 'buy per-query access' slightly obscures the execution action, but the tool name and sequence make the purpose reasonably clear.

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 gives an explicit sequence (data_session_open → data_session_fund → data_session_query) and points to data_preview as a free first taste, which helps an agent choose between the free preview and this paid query tool. It does not explicitly state when not to use this tool, but the sequence and preview mention provide strong practical guidance.

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