MiFID-style best-execution attestation: was this order executed in line with the mandate? (PAID $2.00)

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

Annotations already declare non-readonly, open-world, non-idempotent, non-destructive, so the safety profile is covered. The description adds genuinely new operational context: this is a paid call at 2.00 USD via x402/base/usdc on eip155:8453 through POST /v1/bestex/evidence, which the agent could not infer from annotations or schema. What it does not disclose is whether the attestation is a verdict-only response or whether the payment happens per call on failure too.

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 short lines: purpose front-loaded, then payment/route details. Nothing is padded, though the first sentence is a verbatim copy of the title and the '(PAID $2.00)' tag is immediately restated in the route line.

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?

An output schema exists so return values need not be described, and annotations cover safety. However, for a paid, four-input analytics tool with zero parameter documentation, the description omits what the caller must supply (fills, order, benchmark set) and under what conditions a mandate breach is reported. That is a material gap for an agent deciding whether it can even assemble a valid call.

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% for four top-level parameters, so the description carries the full burden and it does not mention as_of, fills, order, or benchmarks at all. The schema's nested object descriptions ('One fill.', 'The order, the decision, and the mandate it was released under.') supply some meaning, but nothing explains how mandatory fields inside those objects (side, symbol, tolerance_bps, vwap) drive the attestation result.

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 first sentence states a specific verb and resource: it attests whether an order's execution conformed to a stated mandate, in MiFID terms. That is far more informative than a bare name restatement and distinguishes it from siblings like v1_pretrade_risk or v1_mandate_compliance, though it never explicitly contrasts with those near-neighbours.

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?

There is no guidance on when to call this versus v1_mandate_compliance, v1_sla_breach_evidence, or v1_finance_attested_evidence, nor any prerequisites (e.g. required fills/benchmarks data). The only contextual note is the price, which is a cost signal rather than usage guidance.

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