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

Beyond the annotations (readOnlyHint, openWorldHint), the description discloses critical behaviors: SSRF protection blocking private IPs, anomaly detection (JS-heavy SPA, Cloudflare, CAPTCHA, access restrictions), cost per call, and that x711 acts as the browser so no Playwright config is needed. This gives the agent a clear model of what happens and potential pitfalls.

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 longer than necessary but every sentence contributes value: purpose, return fields, anomalies, cost, and sibling pairing. It is front-loaded with the core function and organized logically. Minor promotional language could be trimmed, but it remains efficient.

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 listing the exact return structure, including anomalies and detection flags. It also covers cost, use-case, and the complementary tool. Missing details like error handling or rate limits are not critical for tool selection, so the description is sufficiently complete.

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?

The single parameter 'url' is already fully described in the schema (must be public http/https, SSRF-protected). The tool description repeats the public URL requirement but does not add new parameter-level semantics. With 100% schema coverage, the baseline score of 3 is appropriate.

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 clearly states that the tool observes a public URL and returns a structured intelligence report with specific content types (title, meta, headings, body text, forms, links, images). It positions itself as the agent's 'eyes' and distinguishes from acting or searching tools, making its purpose unambiguous.

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 explicitly names x711_agent_act as the complementary tool to complete the full browser loop, indicating when to use this observation tool versus an action tool. It also implies usage when an agent needs to see a page without browser setup, and the public URL requirement sets a clear boundary.

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