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

The description adds value beyond the annotations by disclosing the API-key requirement, guest-call restriction, REST endpoint, and the preference for open_tx_hash over proof_escrow_id. The annotations already provide idempotentHint and destructiveHint, and the description does not contradict them.

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: purpose, free-trial alternative, auth requirement, parameter preference, guest restriction, and REST endpoint each earn their place. There is no redundant filler, and an agent can extract the key info quickly.

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 covers the essential invocation context: which session to target, which escrow identifier to pass, how to authenticate, who is allowed to call, and the HTTP endpoint. Missing response or error details are less critical for selection and invocation, especially since there is no output schema to reconcile.

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 33%, but the description compensates by naming the escrow identifier options and their preference: open_tx_hash preferred, or proof_escrow_id. It also clarifies that the escrow must be buyer-funded. It does not fully explain how each parameter is obtained or how they interact, but the guidance is sufficient for basic invocation.

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 a specific verb and resource: attaching a buyer-funded proof escrow to an opened data session to buy per-query access. It references data_preview as the free-trial path, which helps differentiate it from one sibling. However, it does not explicitly distinguish itself from sibling tools like data_session_fund or data_session_funding_package, so it stops short of full disambiguation.

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 gives concrete preconditions: an opened data session, an agent API key via Bearer or X-API-Key, and a buyer-funded proof escrow. It also explicitly states the tool is not guest-callable. This is actionable guidance, though it does not spell out when to prefer a sibling tool like data_session_fund or data_session_funding_package instead.

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