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

Annotations already declare destructiveHint and idempotentHint, so the safety profile is covered. The description adds real value on top: an authorization constraint (owners only) and the non-obvious destructive semantic that passing null for the webhook removes it. It does not describe the response or whether a disabled rule still fires existing events.

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?

Two sentences, zero waste, with the actionable scope front-loaded and the consent/permission caveat trailing. Nothing is repeated from the title or schema.

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?

For a three-parameter mutation tool with no output schema and rich annotations, this covers purpose, permissions, and the tricky nullable parameter. It stops short of stating side effects such as whether disabling a rule cancels in-flight alerts, which is a minor gap rather than a blocking one.

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 33%, with rule_id being the sole documented parameter, so the description must carry the rest. It does: 'on/off' explains the enabled boolean and 'null removes it' explains the nullable webhook_url, which is the one genuinely ambiguous parameter.

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 states a specific verb set plus the resource: turn an alert rule on/off or change its webhook. It also implicitly bounds the mutable surface to exactly two fields, which separates it from create_alert_rule and delete_alert_rule among the siblings.

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?

It gives clear context for when to call this (changing enabled state or webhook) and adds an access prerequisite, 'Workspace owners only.' It does not explicitly name alternatives such as create_alert_rule or delete_alert_rule, so the when-not-to-use guidance is left to inference.

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