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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint), and the description adds real behavior the annotations cannot convey: answers come from the registry unless the address is new, fresh=true actually invokes the remote tools now, and that live path is "rationed per caller" (a rate limit). It also discloses that results include citable receipt addresses. Return format details remain thin.

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 trigger condition is front-loaded and every clause carries information — the five enumerated checks are the tool's actual answer set, not filler. The long run-on first sentence is dense and holds all five items in one breath, which costs it a little readability.

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 and only 50% parameter coverage, the description carries the load, and it does enumerate the return facets (answers, tool responsiveness, pricing, injection detection, diffs, receipts). It lacks detail on result shape or what an empty/failed verification looks like, leaving a minor 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 only 50% (url is undocumented), and the description compensates: it defines the address as something "somebody handed you" that is crawled this minute if new, and restates fresh=true as "calls the tools now." The per-caller rationing note adds meaning beyond the schema's terse parenthetical.

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 concretely enumerates what verification yields: reachability, per-tool no-arg responsiveness, pricing, prompt-injection in the card, and tool-list diffs since last look. That is a specific scope an agent can recognize. It does not, however, distinguish itself from near-neighbors like agent_liveness or agent_trust, so it stops short of a 5.

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?

"Before you connect to a server somebody handed you" is an explicit trigger condition, and the description clarifies the registry-vs-live-crawl decision that governs fresh=true. It never names an alternative sibling (agent_liveness, agent_trust) to route between, so no exclusion guidance is offered.

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