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

Goes well beyond the annotations by disclosing the exact cost ($0.005 USDC via x402), that settlement is irreversible ('cannot be undone by this tool'), that it creates a stored report, that the target site is not modified, and that an x402-aware client is required to authorize payment. This explains the destructiveHint/openWorldHint profile in concrete terms an agent can act 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?

Four sentences, each carrying distinct information: selection criteria, cost, settlement behavior, and prerequisites. The most actionable guidance ('Choose this when...') is front-loaded. Slightly dense but 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?

For a paid extraction tool with no output schema, the description covers the return artifact (clean Markdown), the side effect (stored report + settled payment), the precondition (x402-aware client), and the cost. An agent has everything needed to decide and invoke 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% and the description adds no parameter-level detail beyond what the schema already documents (URL constraints and the token budget are fully covered in the schema). Baseline 3 is appropriate since 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?

The description states a specific verb (extract), resource (readable content of a public webpage), and output form (deterministic clean Markdown), explicitly excluding alternatives ('without screenshots or browser execution'). This lets an agent distinguish it from siblings like check_page, compare_page, and verify_page without opening any 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?

The opening 'Choose this when an agent needs...' gives clear positive selection criteria and implicitly narrows the field by ruling out screenshot-based or browser-execution approaches. It does not, however, name a specific sibling as the alternative or state when-not-to-use conditions beyond the output-format contrast.

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