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

The description adds behavioral context beyond the annotations: authentication requirements, guest-call restrictions, preference for open_tx_hash over proof_escrow_id, and the REST endpoint. It does not contradict the annotations, which already mark the operation as non-read-only, non-destructive, and idempotent. The added detail about payment and session binding is useful for the agent.

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 concise and front-loaded with the high-level purpose, followed by auth, parameter preference, and the REST endpoint. Each sentence adds meaningful information. Minor redundancy exists between 'Not guest-callable' and the API key requirement, but the overall structure is efficient.

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 and only sparse parameter documentation, the description should provide more context about expected results, error conditions, or the state after attachment. It covers auth, endpoint, and parameter preference well, but does not explain the response or what happens after a successful attach, leaving moderate gaps for an agent invoking this 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 33%, so the description needs to compensate. It does partially: it explains session_id is an opened session, and it clarifies that open_tx_hash is preferred over proof_escrow_id. However, it does not explain how to obtain proof_escrow_id, whether both can be provided, or what happens if neither is supplied, leaving some ambiguity for a tool with sparse schema documentation.

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 action: attach a buyer-funded proof escrow to an opened data session to buy per-query access. It names the resource (data session) and the escrow object, and identifies the REST endpoint. It does not explicitly contrast with sibling tools like data_session_fund, but the core purpose is unambiguous.

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 clear usage context: it requires an agent API key, is not guest-callable, and should be applied to an opened data session. It also points to data_preview for free access, providing an alternative entry point. It does not explicitly state when to choose this over data_session_fund or data_session_funding_package, but the prerequisites and auth requirements are clear.

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