Set Mailbox Rules

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

The description adds behavioral context beyond annotations by specifying 'replace all' rules, which aligns with destructiveHint=true. It does not contradict annotations. However, it could disclose more about irreversible nature or side effects.

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 concise sentences: first states the core action, second gives usage guidance. No filler words, front-loaded with purpose.

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 complex tool with nested schema and an output schema, the description is adequate but could mention constraints like maximum 50 rules or that existing rules are completely replaced.

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 67%, with the 'rules' parameter lacking a description. The tool description does not add meaning to any parameters beyond what the schema provides, so baseline score of 3 is appropriate.

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 'Replace all server-side inbox rules for a mailbox', using a specific verb ('replace') and resource ('inbox rules'). It distinguishes from sibling tools like shipmail_get_mailbox_rules (read) and other mutation tools.

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 explicitly advises to first use shipmail_get_mailbox_rules to inspect existing rules and folder IDs, providing a clear prerequisite. It does not explicitly state when not to use it or mention alternatives, but the guidance is sufficient.

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