update-mail-rule

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

Annotations set destructiveHint=true and readOnlyHint=false, confirming mutation. The description adds that changes are saved and recommends partial updates (patch behavior), though it could mention error cases. No contradictions.

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 plus a tip. Every part is useful, no redundancy. Information is front-loaded with the core purpose immediately explained.

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, but the description does not mention what the response contains (success indicator or updated rule). For a mutation tool, this is a notable gap. However, the tip and parameter guidance are otherwise thorough.

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 80%, and the description adds value by highlighting the body parameter and common fields like isEnabled. It explains the partial update pattern, going beyond the schema 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?

The description states 'Change writable properties on a messageRule object and save the changes.' This clearly defines the action (update) and resource (message rule), distinguishing it from sibling tools like create-mail-rule or delete-mail-rule.

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?

The tip advises using the Inbox folder ID from list-mail-folders for inbox rules and to 'Send only the properties to change.' It provides a common use case (disabling a rule), but does not explicitly state when not to use this tool or alternatives.

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