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

Annotations only cover the safety profile (readOnly, openWorld, non-destructive), yet the description goes further: exact cost (~$0.006), budget cap semantics with defaults, that chargedUsd reports actual spend, the robots-block caching fallback, and the required write scope. That is rich behavioral disclosure beyond structured fields.

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?

Three dense sentences, front-loaded with what is returned and only then cost and auth. Every sentence carries distinct information, though the cost/budget/chargedUsd clause is slightly compressed and takes a re-read.

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 an output schema present, return values needn't be detailed, and the description covers cost, auth, and fallback behavior. The only missing piece is explicit sibling routing, which keeps it from a 5.

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 the baseline is 3, but the description adds value by tying budgetUsd to a cost model and an output field (chargedUsd) not visible in the input schema, giving the agent reason to set a budget rather than treat it as a bare number.

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 ('full clean text of a URL') and distinguishes itself from text-free siblings like screenshot_page and record_page by emphasizing extracted text. The cached-copy qualifier adds scope precision that an agent can act on.

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 — fetch readable text of a known URL — and the caching fallback hints at a robustness behavior, but no sibling is named and there is no explicit when/when-not guidance versus web_search, reference_read, or screenshot_page. Adequate but with a clear routing gap.

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