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

No annotations are provided, so the description carries the full burden. It usefully discloses that there is no network access, that the checks are identical to lint_x402_endpoint, and that it is free, but it says nothing about the shape of the lint results (findings, severities, pass/fail) and there is no output schema to fall back on.

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 sentences, front-loaded with what is linted, then the accepted formats, then the differentiators (no network, free). No filler or redundancy.

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?

Covers input formats, the network-free contract, parity with the sibling, and cost — enough to invoke correctly for a simple validator with two params and no side effects. The one real gap is the return value, since no output schema exists to describe the lint findings.

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 100%, so both parameters are already documented. The description restates the accepted forms of payment_required (JSON object, JSON string, raw base64 header) and never mentions the optional url parameter, which only the schema explains. Baseline 3 is appropriate when the schema does the work.

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 (lint) and a specific resource (a PaymentRequired object you already hold), and enumerates the three accepted input encodings. It also names the sibling lint_x402_endpoint and the axis that separates them (no network access), so an agent can pick without opening either schema.

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?

"A PaymentRequired object you already have" plus "no network access" clearly signals the condition that selects this tool over lint_x402_endpoint, which presumably fetches a URL itself. It stops short of an explicit "use lint_x402_endpoint when you only have a URL" statement, so the routing is inferred rather than spelled out.

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