Timbre

by alejandrosml

Overview Schema Source Related Servers Discussions Admin

Rust

Local

list_rules

Read-only

Lists Apple Mail rules in order, showing each rule's name, enabled status, conditions, and actions in plain language.

Instructions

Mail's rules, in order: each one's name, whether it is on, its conditions and actions in words.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_rules"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description	Default
`rules`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.7.2Nov 9, 2026

TDQS

A3.9/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real context beyond them: results come back ordered, and conditions/actions are rendered in words rather than raw structures, which tells an agent what fidelity to expect.

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?

A single sentence fragment with zero filler, and the most important qualifier ("in order") is placed immediately after the resource. Nothing could be removed without losing 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?

With an output schema present, return-value detail needn't be spelled out, and the read-only nature is covered by annotations. The one remaining gap is the absence of any routing guidance relative to the rule-mutating siblings, but for a no-arg list operation the definition is otherwise sufficient.

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

Parameters4/5

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

There are zero parameters, so there is no parameter semantics to add; the schema is empty and needs no compensation. Baseline 4 applies for a no-arg tool.

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

Purpose4/5

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

The description names the resource (Mail's rules) and the operation (listing), and adds a meaningful ordering guarantee ("in order"). It does not explicitly distinguish itself from siblings like create_rule or change_rule, though the verb makes the read-only listing intent obvious.

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?

Usage is only implied: an agent can infer this is the way to inspect existing rules before calling change_rule or create_rule, but the description never says so or names an alternative. No when-not-to-use guidance or prerequisites are given.

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