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

Annotations already cover safety (readOnly, idempotent, openWorld, non-destructive), and the description still adds real context beyond them: checks originate from an edge network, up to 10 URLs, results include a CSV download, and a site may block the check. It also discloses hard limits — no IP literals, no private/reserved addresses, only ports 80 and 443 — which the annotations do not convey.

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?

Front-loaded with the user phrasings that should trigger it, followed by capability, then limits and exclusions in a clear order. It is a dense run-on sentence with a long trigger list, but every clause carries routing or constraint information.

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?

For a single-parameter read tool with an output schema and full annotations, the description covers everything an agent needs: what it returns, throughput limit, output format (CSV), and the failure modes that would otherwise cause a wasted call. Return-value detail is a bonus, not a gap.

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%, so the single 'urls' parameter and its 1–10 bound and accepted formats are already fully documented in the schema. The description's 'for up to 10 URLs' merely restates maxItems, adding no new parameter semantics — baseline 3 applies.

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 ('makes a live request from the edge network') and enumerates the exact verdict fields returned (redirect chain, HTTP status, response time, TLS, page title, security headers). It does not explicitly distinguish itself from the sibling check_security_headers, even though security headers are listed as one of its outputs — overlap an agent must resolve on its own.

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?

Gives concrete trigger phrasings ('is it down', 'website status') and explicit exclusions (no monitoring, no uptime history, no internal/private addresses), which is unusually strong routing guidance. It stops short of naming the sibling check_security_headers as the alternative for header-focused queries, so the alternative-selection half of the criteria is incomplete.

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