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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description's main added value is the commercial behavior: the $0.005 price (5000 atomic USDC on Base) and x402 payment flow, which the agent would otherwise not know before invoking. It does not cover failure modes such as what happens if payment fails or the text exceeds its limit, so it stops short of full transparency.

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: the capability and its outputs come first, and the payment terms follow immediately. Every clause carries information an agent needs, with no filler.

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?

With no output schema, the description usefully summarizes the return shape (a 0-100 score plus top 3 fixes) and discloses the payment requirement. For a single-parameter tool this is nearly complete; only the payment-failure behavior and any latency or retry expectations are unstated.

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?

Only one parameter, and the schema already documents it fully at 100% coverage including the 'max 4000 characters' constraint. The description adds nothing about the input beyond what the schema states, so the baseline of 3 applies.

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 ('Score a draft 0-100') and names the exact scoring dimensions (clarity, voice, concision) plus the deliverables (top 3 fixes). An agent can distinguish this from the sibling voice_rewrite, which rewrites rather than scores, 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?

Usage is only implied: it is evident the tool is for evaluating a draft, but the description never says when to pick this over voice_rewrite, nor any when-not conditions or prerequisites. No explicit routing guidance to a sibling is given.

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