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

Annotations already flag destructiveHint=true and non-idempotent, so safety is covered. The description adds genuinely new behavioral context: that each scan spends the quoted credit price once, and that the quote values are required for the enabling path. This is meaningful cost/consumption disclosure beyond annotations.

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?

Three short sentences, no filler. The default state and the owner-approval constraint are front-loaded, followed by the cost mechanics, which is the right order for an agent making a decision.

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?

There is no output schema, all three params are documented at 100% coverage, and annotations carry the destructive/idempotency profile. The description supplies the default state and spending semantics. It could note what happens to existing schedules or what a successful response looks like, but overall it is sufficient to call correctly.

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 coverage is 100%, so the baseline is 3. The description adds conditional meaning the schema doesn't: credits and pricingVersion are only needed when turning on, and must come from the same quote the owner saw ('each scan spends that once'), which clarifies their purpose beyond the terse schema field descriptions.

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 concrete verb and resource with the exact enum values ('Turn scheduled scans off, daily or weekly'), which lets an agent distinguish this schedule-setting tool from the one-off scan siblings. It stops short of naming those siblings explicitly, but the purpose is 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?

'Off by default; turn on only when the owner asks' gives explicit when-to-use and when-not guidance, plus the precondition that enabling requires credits and pricingVersion from the quote the owner saw. It doesn't name the sibling tool that produces that quote, so an agent must infer it, keeping this just below a 5.

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