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

Adds real context beyond the annotations: it discloses the billing consequence ("Billed like a scheduled check") and an auth prerequisite ("Needs a free SnoopScan key"). Annotations already cover readOnly=false, openWorld=true, idempotent=false, so the incremental disclosure here is the cost and credential profile, which matters for a non-idempotent action.

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 action and the result categories, then the two operational caveats. Very short and every sentence earns its place, though the fragmented blank-line layout makes the credential note read like an afterthought.

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?

An output schema exists so return values need not be detailed, and the description still previews the outcome categories. Billing and auth are covered; the only meaningful gap is where monitorId comes from and what happens on a failing/invalid monitor.

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 0% and the description never explains monitorId — how to obtain it, its format, or whether it must come from listMonitors. It only implies the parameter identifies "a monitor," which is already obvious from the name; nothing compensates for the coverage gap.

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+resource ("Run a monitor's check now") and enumerates the outcome classes reported (new/changed/unchanged/failing), which is more than a restatement of the title. It differentiates from listMonitors by being an execution action rather than a listing, though it never explicitly names a sibling it is not.

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?

Usage is only implied: the phrase "check now" suggests forcing an out-of-band run versus the scheduled checks, and "Billed like a scheduled check" hints at a cost tradeoff. No alternative (listMonitors, watchPages, checkChanges, crawlStatus) is named and no when-not condition is given.

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