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

Beyond the annotations (idempotent, non-destructive), the description reveals authentication requirements, guest restrictions, and the REST path. This adds meaningful behavioral context without contradicting the annotation-provided hints.

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?

Three sentences, each earning its place: the value proposition and free alternative, the auth requirement, and the core action with the REST endpoint. No fluff or redundant restating of the schema.

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 auth, endpoint, prerequisite session, and escrow identifier preference. It does not clarify whether one escrow identifier is mandatory or what happens on repeated attachment, but annotations and the idempotent hint partially cover that gap.

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 only 33%, so the description must compensate. It does by explaining that open_tx_hash is preferred over proof_escrow_id and that these identify the buyer-funded escrow. This is useful, though it leaves ambiguity about whether at least one is actually required despite the schema listing them as optional.

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. It also mentions the REST endpoint and distinguishes itself from data_preview, making the tool's purpose unmistakable.

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 provides clear context: requires an agent API key, is not guest-callable, and must be used with an already-opened session. It also points to data_preview as the free alternative, giving a sense of when to choose this tool, though it does not explicitly name data_session_fund as an alternative.

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