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

The annotations only signal non-read-only behavior, so the description adds useful behavioral context: the session is prepaid, per-query priced, and capped at 20 queries per session. It does not disclose whether a wallet transaction is required, what the return value is, or the consequences of opening an unfunded session, making this partial rather than complete.

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?

Two sentences front-load the core purpose and pricing, then give the workflow. The listing-specific example is useful but slightly narrows what is otherwise a general tool description.

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 five parameters, no output schema, and no per-parameter documentation, the description is too sparse for an agent to safely construct a valid call. It lacks input formats, expected return values, and the dependency relationship with funding/escrow steps, so the workflow narrative alone is not enough.

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 0%, and the description never names listing_id, buyer_address, max_queries, open_tx_hash, or proof_escrow_id. The mention of 'ghtrend' and 'max 20 queries/session' gives hints about listing_id and max_queries, but the required buyer_address and the transaction/escrow parameters remain unexplained.

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 a concrete action ('open a prepaid session') and a concrete resource ('data listings', specifically the ghtrend listing), so an agent can tell what the tool does. It doesn't sharply differentiate from sibling session tools like data_session_fund or data_session_query beyond the workflow sequence, which keeps it from a 5.

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 explicitly points to data_preview as the free first step and places this tool in a clear sequence: open a session, then fund and query. It doesn't discuss when to prefer data_session_attach_escrow or data_session_funding_package, so the guidance is context-rich but not exhaustive.

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