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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds material context beyond them: ADMIN-only auth, that destinations are not stored on the rule but forwarded to the notification gateway, and that unknown channel ids are rejected with no change. It does not explicitly reaffirm the idempotent/replace semantics, but the 'replace'/'forwarded' wording is consistent with the 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?

Purpose and the bold 'WRITE: ADMIN only' flag are front-loaded, then parameters, then behavioral notes. Despite its length every sentence carries distinct information (inheritance, off-switch, precedence, validation).

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?

No output schema exists, yet the description covers everything an agent needs for a mutation call: auth level, destination source, inheritance/clear semantics, invalid-id behavior, and where to read the current value. Nothing material is missing.

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 baseline is 3. The description adds real value beyond the schema: channelIds must be registry channel UUIDs from list_alert_channels, explicitly NOT Slack channel ids, and it clarifies the two distinct empty-vs-omit behaviors even though the schema already hints at them.

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 ('Replace where one alert rule's alerts are delivered') and explicitly scopes it to routing only, declaring the rule's spec and status untouched. This clearly distinguishes it from siblings like set_alert_rule_status, save_alert_rule, and set_notification_destinations.

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 explicit when-to-use semantics: omit/null to inherit tenant default, empty list to switch off, and names the alternative (set_notification_destinations with source alerting) plus the read counterpart (get_alert_rule_destinations). Precedence ('A per-rule setting outranks the source-level one') is spelled out.

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