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

Annotations mark destructiveHint=true and readOnlyHint=false, and the description adds valuable context beyond annotations: it specifies the return shape ({ action_performed, result, page_status }), mentions a 'JS SPA warning included if detected', and discloses operational requirements (cost $0.05, requires API key). It aligns with the destructive hint without contradiction, and discloses side-effect potential via 'fills and submits forms'.

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 description is dense but well-organized: hook, what-it-does, no-setup assurance, synergy with see, examples, return format, warning, and cost/auth. Each sentence serves a purpose, though the triple 'No Playwright. No Puppeteer. No browser setup.' is slightly repetitive and could be condensed. Front-loaded with purpose, so it earns a 4 rather than 5.

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 compensates by specifying the return object, includes cost and API key requirements, and notes the SPA warning—a practical caveat for browser automation. It does not cover potential errors or rate limits, but given the presence of annotations for idempotency/destructiveness and the tool's open-ended nature, it is sufficiently complete for an agent to invoke 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 coverage is 100% for all three parameters, so baseline is 3. The description adds value by reinforcing the URL+instruction pattern, providing natural-language instruction examples, and clarifying the tool's purpose, which enhances understanding of the 'instruction' parameter. It slightly goes beyond the schema's examples by framing them as real-world use cases, thus warranting a 4.

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 opens with a clear, specific verb-resource pair ('Give any agent hands. Pass a URL + natural-language instruction → x711 executes it'), enumerating concrete actions (fills/submits forms, follows links, extracts structured data) and differentiates from sibling x711_agent_see by explicitly positioning it as the 'act' counterpart in a two-tool browser pair. This is unambiguous and immediately distinguishable.

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 explains when to use it ('Together with x711_agent_see this is a full browser in two tool calls... navigate the entire internet autonomously'), provides example instructions, and contrasts with browser-setup overhead ('No Playwright. No Puppeteer. No browser setup.'). It does not list exclusions or alternatives like x711_web_search, but the complementary relationship to see is explicit.

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