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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuinely non-structured behavior: it discloses the return shape (top passages with heading and word count) and a concrete quotable-length rule of 40 to 90 words. That is real added value, though nothing is said about fetch failures, blocked pages, or how many passages are returned.

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?

Two sentences, zero waste, and the primary purpose is front-loaded before the return-shape and usage details. Nothing is repeated from the title or 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 usefully compensates by describing what comes back (passages plus heading, word count, quotable-length flag) and how to act on it. Combined with annotations covering the safety profile, an agent has enough to call it correctly, though limits on result count and failure modes are absent.

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 description coverage is 100% and both parameters are documented in the schema with examples, so the schema carries the burden. The description adds no parameter-level detail (no URL normalization, no question phrasing guidance) beyond what the schema already states, making the baseline 3 correct.

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 ('Find the passages on a page that best answer a given question') and adds a framing device — 'the way AI answer engines pick text to quote' — that meaningfully sharpens what kind of passages are returned. It stops short of naming or distinguishing itself from nearby siblings like check_snippet or check_ai_visibility, so an agent still has to infer the boundary.

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 second sentence gives downstream usage ('judge whether the page answers the question well... rewrite the best passage into a direct answer'), which implies context but is about what to do with output rather than when to select this tool over alternatives. No explicit when-not or alternative is named among the ~19 siblings, leaving the routing decision to inference.

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