Retrieve permitted Apple Mail accounts and their stable IDs, so you can identify which accounts are available for searching and reading email on macOS.
List permitted Apple Mail accounts and their stable IDs.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds meaningful context with 'permitted' (implying permission scoping) and 'stable IDs' (implying persistent identity across calls), which is beyond the annotations, but it does not discuss ordering, empty results, or account states.
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?
A single compact sentence with the resource and the key output characteristic front-loaded. No filler, no redundancy.
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 no-parameter list tool with annotations covering the safety profile and an output schema covering the return shape, this description is nearly sufficient. It could add a note on ordering or on what 'permitted' means in practice, but nothing an agent needs to invoke it correctly is missing.
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?
The tool takes zero parameters, so per the rubric the baseline is 4. With 100% schema coverage and no inputs to explain, there is nothing further the description could add here.
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 gives a specific verb ('List') and resource ('permitted Apple Mail accounts') plus a useful output detail ('stable IDs'), which cleanly separates it from siblings like list_mailboxes and search_messages by resource type. It stops short of explicitly naming a sibling, but the resource is unambiguous.
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?
There is no guidance on when to call this versus alternatives such as list_mailboxes, nor any stated prerequisites or context. The sentence only describes what the tool returns, leaving the agent to infer usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.