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

Beyond the readOnly/idempotent annotations, the description discloses redirect following, refusal of non-text content, the 2 MB cap, and the operational cost/auth model with x-credit-token. These are concrete behavioral constraints an agent would not otherwise know. There is no contradiction with the annotations.

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?

The core behavior is front-loaded, and the pricing/auth details are conveniently placed at the end. The description is slightly wordy with marketing lines such as 'The step every agent needs...' and 'Nothing crypto about it,' but most included details serve an operational purpose for a paid tool.

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 and annotations already conveying readOnly and idempotent behavior, the description covers the input, output contents, constraints, and access/cost model. Nothing essential for making a correct first call is missing; maxChars ambiguity is minor because the schema already provides its basic meaning.

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. The description only restates that url is required and adds a general 2 MB limit, without clarifying how maxChars interacts with the output length. It does not materially improve on the schema's parameter descriptions.

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?

Pass a URL and get the page as clean text is a specific verb-resource-outcome statement. It details what is stripped and preserved, so the tool's purpose is unmistakable. It does not explicitly name sibling tools like url_to_json or web_extract, so it falls just short of full sibling differentiation.

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 description clearly explains when the tool is needed: before an agent can reason about a web page, especially in serverless/MCP runtimes that lack a browser or HTML parser. It also states exclusions such as refusing non-text content and capping at 2 MB, though it does not name alternative tools for related tasks like web search or structured JSON extraction.

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