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

With no annotations, the description carries the full burden and does add real behavioral context: the proof is registry-signed, the outputs are counts/dispute rate, receipts are not disclosed, and there is an x402 payment cost of $0.05 per 1,000 receipts. It omits what happens on payment failure or how the charge is assessed, but the pricing and privacy disclosures are substantive.

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 tight sentences, front-loaded with the resource and result shape, followed by the cost. Slightly cryptic phrasing ('no receipts surrendered', 'the set') costs a little clarity for its brevity.

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?

No output schema, no annotations, and a two-param schema with zero descriptions, so the description must do more than it does. It tells the agent what is proven and what it costs, but leaves output structure and task_class semantics unspecified.

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 0%, so the description must compensate and largely doesn't. It references 'agent's history' (agent_id) and 'the set' (presumably task_class scoping), but never explains what task_class does or whether it narrows the aggregation — an agent could easily pass it or omit it with no clear expectation.

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?

States a specific verb and resource: an aggregate proof over an agent's history, registry-signed, yielding counts and dispute rate. It's distinct enough from verify_proof/verify_receipts, but it never names those siblings, so the differentiation is left implicit.

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 parenthetical 'no receipts surrendered' implies the use case (privacy-preserving aggregate instead of per-receipt verification) but the description never states when to choose this over verify_proof or verify_receipts. Usage is inferable rather than directed.

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