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

With annotations present, the description goes well beyond them: it discloses that no POST is submitted, no worker assigned, no result delivered, no execution authority or proof verification created, and that server credentials are never supplied. This is meaningful behavioral context. It is not a contradiction that readOnlyHint=false coexists with 'no execution authority', since durable payment-access records are explicitly disclosed as a write side effect.

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 entry is bloated and repetitive: 'grants no authority', 'creates no execution authority', and 'bounded computation on caller-supplied data' are restated three times. Payment terms are front-loaded before the tool's actual purpose, so the definition is not well front-loaded for selection.

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?

For a 5-required-parameter, nested-object tool with no output schema and no parameter descriptions, the description covers behavioral boundaries well but leaves parameter semantics entirely unexplained. An agent cannot reliably populate mode, product_key, or requested_outcome from this definition alone, so it is incomplete for correct invocation.

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% across 5 required parameters, so the description must compensate and largely does not. It does not explain mode (the const), product_key (the enum of supported products), requesting_agent_id, or requested_outcome; only 'task' is obliquely referenced via 'validate a task'. An agent must open the schema and guess at semantics.

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 sentence 'Validate a task against a supported computation and prepare its fixed POST request' gives a specific verb+resource and scope, and 'No request is submitted, worker assigned or result delivered' sharply bounds what the tool does versus post-commit siblings. It is clear enough to distinguish from execution-oriented siblings, though the core purpose is buried mid-paragraph under payment boilerplate.

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 sketches an operating boundary (x402 Base USDC settlement or verified-wallet free tier, with existing credentials/signed grants required for consequential actions), which implies when to use it. However, it never names or contrasts an alternative sibling (e.g. work-order-rail, paid-workflow, x402-payment-gateway), so the routing decision is left to inference.

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