create-rule

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

Discloses that the rule automatically acts on real mail with potential destructive actions (delete, move) and advises user confirmation. However, does not mention error handling, idempotency, or behavior when a rule with the same name exists. No annotations are provided, so the description carries the full burden.

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 with no wasted words. Structured into clear sections: use case, return info, alternatives, and safety. Front-loaded with the most important information.

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 no annotations and no parameter descriptions in the schema, the description covers usage, return value, behavior, and safety adequately. Only minor omissions (e.g., default for enabled) but overall very complete.

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 0%, but the description adds meaning for all key parameters: explains conditions structure (field/operator/value), actions (markRead, markFlagged, delete, moveTo, moveToAccount), and matchAll logic. It compensates fully for the lack of 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?

Clearly states the verb 'creating' and resource 'Mail rule'. The description explicitly distinguishes this tool from siblings like enable-rule, disable-rule, delete-rule, and list-rules by mentioning when not to use.

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?

Provides explicit 'Use when:' and 'Do not use when:' guidance with specific alternative tool names (enable-rule, disable-rule, delete-rule, list-rules). This helps the agent decide when to invoke this tool.

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