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

Annotations already declare idempotentHint=true and readOnly=false; the description adds important behavioral context by disclosing the $0.50 price, the challenge-then-signature flow, and at-most-once retry semantics. The wording around 'required' vs 'recommended but optional' for _salt19_operation_id is slightly ambiguous, but it still goes well 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 compact and front-loads the core decision output, price, and retry protocol. Every sentence serves a purpose, though the relationship between 'required' and 'recommended but optional' could be phrased more cleanly to avoid a mild internal tension.

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?

Given the tool's paid, retry-sensitive nature and the presence of an output schema, the description covers the essential operational protocol: cost, challenge handling, operation id preservation, and the decision output. It is complete enough for an agent to invoke correctly, aside from not clarifying how it relates to sibling preflight tools and the slight optionality ambiguity.

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 100%, so the baseline ismet. The description adds real value for _salt19_operation_id and _x402_payment_signature by explaining their lifecycle across challenge, retries, and payment, which the schema does not convey. It does not elaborate on target/constraints, but those are already adequately described in the schema.

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 opens with a concrete action: return a bounded GO, WARN, or BLOCK decision with evidence and a portable SALT19 verification receipt, scoped to 'before an autonomous coding agent installs or adopts software.' This clearly states what the tool produces and when it applies, though it does not explicitly differentiate itself from similarly named preflight siblings.

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 gives a clear invocation context ('Before an autonomous coding agent installs or adopts software') and adds operational guidance for the x402 flow: generate and preserve a _salt19_operation_id, then add _x402_payment_signature after the challenge. It does not mention exclusions or alternative sibling tools, so it stops short of a full routing guide.

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