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

Annotations already declare idempotentHint=true and destructiveHint=true, so the safety profile is covered structurally. The description adds genuinely non-redundant behavior: already-cancelled rows are no-ops and out-of-scope targets return not_found rather than erroring — useful expectations beyond the hints. It does not say whether cancelling a schedule also cancels its pending reminder instances, which is the main remaining ambiguity.

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: the action/mode split comes first, then idempotency, then the authorization caveat. No filler and nothing buried.

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?

Returns are covered by an existing output schema, and the description closes the two biggest gaps for a destructive, scoped mutation: idempotency and reachability. The only meaningful omission is the cascade question (does schedule cancellation affect already-scheduled reminder rows?), which matters for a destructiveHint tool.

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 all three parameters (including the tenant_slug fallback guidance) are already fully documented in structured fields. The description's mention of reminder_id/schedule_id only restates the schema's mutual-exclusivity note and adds no format or edge-case meaning beyond it; 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 the specific verb (cancel) and both resources (single reminder via reminder_id, entire schedule via schedule_id), with the parameter that selects each mode named inline. An agent can distinguish this from kb_reminders_list/get/create without opening the schema.

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?

Explains the two mutually exclusive cancellation modes and how to pick between them, plus the scoping rule that only reminders/schedules you created or receive are reachable. It stops short of naming alternatives (e.g. kb_reminders_get/list for discovering IDs) or telling the agent when not to use this at all.

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