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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantial behavior beyond them: a 40-link check ceiling with the remainder 'skipped', robots.txt compliance, the full totals returned, and an explicit pricing/billing model ($0.003 USDC via x402, failed calls not charged). The billing and capping details are exactly the kind of context annotations cannot carry.

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?

Dense but front-loaded: the core capability leads, followed by return fields, the check cap, scope, robots.txt, and pricing. Every sentence carries operational information 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?

Given an output schema already exists, the description need not explain return values, yet it still sketches the result shape and totals. Combined with the billing, cap, and robots.txt disclosures, an agent has everything needed to call it 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?

Schema description coverage is 100%, so the schema already documents url and scope. The description restates the scope values (all/internal/external), which duplicates rather than extends the schema, though the 'up to 40' limit adds meaningful constraint context. Baseline 3 is appropriate when the schema does the heavy lifting.

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: extracting every link (anchor text, internal/external) from one page plus a status check of up to 40. This is clearly distinguishable from siblings like redirects, sitemap, headers, and dns, which handle related but different concerns.

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 implied by the capability (audit a page's links), and the 40-link cap hints at its bounded scope, but the description never says when to prefer this over redirects, sitemap, or audit, nor does it state prerequisites beyond robots.txt being respected. No explicit when/when-not routing.

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