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

Annotations already mark the call as non-read-only, idempotent, and non-destructive. The description adds that this is a paid operation, requires authentication, and is not guest-callable, which gives useful behavioral context beyond the annotations.

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 fairly compact but contains a promotional opening sentence and repeats the authentication requirement with 'Requires an agent API key' followed by 'Not guest-callable'. Some redundancy could be trimmed without losing clarity.

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?

It covers prerequisites such as an opened session, funded escrow, and API key, and references data_preview. However, it does not mention expected output, error behavior, or the relationship to data_session_fund and funding_package, which would help an agent fully plan a workflow.

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?

Only session_id has a dedicated schema description. open_tx_hash and proof_escrow_id are explained mainly by their names and the phrase 'open_tx_hash preferred, or proof_escrow_id', but the description does not clarify where these values come from or what happens if both or neither are supplied.

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 identifies the action: attach a buyer-funded proof escrow to an opened data session. It also distinguishes the tool from data_preview by mentioning the free taste, and the operation is distinct from sibling tools like fund or open.

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 states the key precondition (an opened data session), requires an agent API key, and points to data_preview for free access. It does not explicitly contrast with data_session_fund or funding_package, but the intended sequencing is reasonably clear.

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