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

The description discloses auth requirements, guest restrictions, and the fact that this buys per-query access, which go beyond the annotations. It does not mention rate limits or reversibility, but the annotations already carry idempotentHint=true and readOnlyHint=false, so the added context is valuable and consistent.

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: purpose, auth, prerequisite, parameter preference, and REST endpoint all appear in three sentences. It is front-loaded with the high-level buying access purpose, and every sentence adds information without redundancy.

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?

For a 3-parameter tool with no output schema, this description covers the essential context: API key requirement, guest restriction, session prerequisite, escrow parameter choices, and REST path. It does not describe the response or follow-up querying tool, but annotations and sibling tool names make invocation sufficiently clear.

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 coverage is low at 33%, so the description must compensate. It does map open_tx_hash and proof_escrow_id to 'buyer-funded proof escrow' and expresses a preference, which helps. However, it still leaves their exact provenance unclear — e.g., what open_tx_hash is the hash of or how to obtain proof_escrow_id — so it only partially compensates.

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 states a specific verb and resource ('Attach a buyer-funded proof escrow to an opened data session') and clarifies the broader purpose ('Buy per-query access to live data listings'). It distinguishes itself from the sibling data_preview by saying 'first taste free via data_preview', so an agent can tell which tool serves which need.

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 clear usage context: requires an agent API key, is not guest-callable, and applies to an already-opened data session. It also names a free alternative (data_preview) and states a parameter preference (open_tx_hash preferred over proof_escrow_id), though it does not explicitly list when-not-to-use conditions.

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