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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower, and the description still adds real behavioral context: headless-browser rendering of the URL, LLM-written output, the available output shapes, and the $0.0045 USDC x402 cost per call. Cost and payment mechanism are exactly the kind of trait annotations cannot express.

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 the core capability, then mechanism, then output options, then cost. No filler and nothing redundant with the schema.

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 no output schema, the description carries the burden of explaining what comes back, and it does so via the style definitions and "faithful summary." It also covers cost and input modes. The remaining gap is the url-vs-text precedence rule, which an agent would need if both are supplied.

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 67%, so the schema documents the fields but thinly — the style values are only listed as tokens. The description defines what each style produces (2-3 sentences, one paragraph, bullets) and confirms the default, which adds genuine meaning beyond the schema. It does not clarify whether url and text are mutually exclusive or how conflicts resolve.

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: "Summarize any web page or long text," and adds the mechanism (headless browser render + LLM summary). An agent can identify what it does, though it never distinguishes itself from adjacent siblings like extract, scrape, or ask.

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 phrase "any web page or long text" implies the input contexts where it applies, but there is no explicit when-to-use/when-not guidance and no named alternative for cases like plain text extraction or Q&A over a page. Usage is inferable but not directed.

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