update-mail-rule

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

Annotations declare destructiveHint=true and readOnlyHint=false. The description adds that changes are saved (mutation) and suggests partial updates via 'send only the properties to change' and 'Common use: { isEnabled: false }'. This supplements annotations well without contradiction.

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?

The description is concise: three sentences and a tip, front-loaded with the main action. Every sentence contributes meaning without repetition or fluff.

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?

Given the complex nested input schema and no output schema, the description covers the essential workflow (partial update, folder ID needed). It lacks mention of error handling or the simplified conditions note, but is sufficient for a capable agent to invoke the tool 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 high (80%). The description adds value by explaining mailFolderId usage (Inbox folder ID) and giving an example for body (isEnabled). However, it does not detail other critical nested parameters like conditions or actions beyond a tip, leaving some burden on the schema.

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 clearly states the tool updates an existing message rule (verb 'change' + 'messageRule object'), distinguishing it from create-mail-rule or delete-mail-rule. The tip reinforces the purpose by giving a common use case (disable a 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 description provides specific guidance: use the Inbox folder ID for inbox rules, send only properties to change, and gives a common use case. It implies when to use (update) vs. alternatives (create/delete) but does not explicitly exclude other scenarios.

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