mail-mcp

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delete_rule

Destructive

Permanently delete a Mail.app rule using its rule ID. A timestamped backup is created so deletion can be undone if needed.

Instructions

Permanently delete a Mail.app rule by its RuleId. A timestamped backup of SyncedRules.plist is made before writing so the deletion can be undone. Mail.app may need to be restarted for the change to take effect.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "rule_id": "<rule_id>"
    },
    "name": "delete_rule"
  }
}

Input Schema

Name	Required	Description	Default
`rule_id`	Yes	The RuleId of the rule to delete (from list_rules).

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.2.0May 10, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already indicate destructiveHint=true. Description adds valuable context: timestamped backup is made, and Mail.app may need restart. Provides useful behavioral details beyond annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no redundancy. Front-loaded with purpose. Every sentence provides essential information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Single parameter, no output schema. Description covers purpose, backup, and restart requirement. Minor gap: does not specify what happens if rule_id is invalid, but adequate for its complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema covers 100% of parameters with description. The description adds that rule_id comes from list_rules, which is a helpful hint. Baseline 3 is appropriate as schema already does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the action (permanently delete), resource (Mail.app rule), and identifier (RuleId). Distinguishes from sibling tools like create_rule and update_rule.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No explicit when-to-use or when-not-to-use guidance. Lacks context about prerequisites or alternatives. The description is adequate but could specify scenarios where deletion is appropriate.

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