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

Annotations only declare readOnlyHint=true, so the description carries the rest and does well: it discloses the payment model and price per call (x402, $0.01 USDC) and that the 18 checks are fetched in parallel, which hints at latency behavior. It stops short of stating rate limits, failure modes for unreachable URLs, or the recommendation payload's format.

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?

Front-loaded with the outcome (score, grade, 18 checks) and then the check categories, ending with the price. It is a dense single passage and each clause conveys distinct coverage, though the long enumeration of discovery files is close to overload for a field that could be summarized.

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?

No output schema exists, yet the description defines what comes back (0-100 score, A-F grade, concrete recommendations) and enumerates what is inspected, including the parallel-fetch behavior and the per-call price. For a one-parameter read-only audit tool, an agent has everything needed to decide and call correctly.

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?

There is a single parameter (url) already fully documented in the schema as "Public http(s) URL of the site or page to audit." The description adds no additional semantics such as whether redirects are followed, whether the URL must be a page versus a host root, or validation behavior. With 100% schema coverage, the baseline 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 ("Agent-readiness audit of a website") and immediately defines the output shape: a 0-100 score and A-F grade from 18 checks. The enumerated check categories (robots.txt bots, llms.txt, discovery files, on-page signals) make the scope unmistakable and leave no ambiguity against unrelated siblings like deps_audit or dns.

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?

Implies the usage context clearly — call it with a public site/page URL to get an agent-readiness score plus recommendations. It also gives a cost precondition ($0.01 USDC via x402) that an agent must weigh before invoking. No explicit when-not-to-use or alternative routing is given, but no sibling tool plausibly overlaps.

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