Proton Suite Agent

List mailboxes (folders/labels)

proton_list_folders

Read-onlyIdempotent

Lists all Proton Bridge IMAP mailboxes, including system folders and user labels, and returns path values to use as mailbox arguments in other tools.

Instructions

Lists every IMAP mailbox exposed by Proton Bridge (system folders like INBOX/Sent/Trash and user labels/folders). Use the returned 'path' values as the mailbox argument in other tools. Call this first when the agent doesn't know the mailbox layout.

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": "proton_list_folders"
  }
}

Input Schema

Name	Required	Description	Default
`response_format`	No	Output format	markdown

Output Schema

Name	Required	Description	Default
`folders`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv1.7.4Oct 28, 2026
- removedOutput schema / properties / folders / items / properties / delimiter / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / folders / items / properties / delimiter / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / folders / items / properties / specialUse / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / folders / items / properties / specialUse / type
```
Added value: +[
+  "string",
+  "null"
+]
```
First observedv0.8.0Jul 28, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered; the description adds that results come from Proton Bridge's IMAP exposure and that 'path' values are the canonical mailbox identifiers. It does not describe ordering or pagination, but for a small enumerable list that is minor.

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?

Three sentences, front-loaded with the core action, followed by practical usage of the return value and the routing condition. No redundant or filler text.

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

Completeness5/5

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

A read-only enumeration tool with an output schema, full schema coverage, and annotations covering safety. The description supplies the one thing structured fields cannot: how the returned 'path' feeds into other tools.

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?

Only one optional parameter (response_format) with an enum and 100% schema description coverage, so the schema fully documents it. The description adds no parameter-level meaning, which is acceptable at this coverage baseline.

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?

States a specific verb and resource ('Lists every IMAP mailbox exposed by Proton Bridge') and enumerates the two categories returned: system folders (INBOX/Sent/Trash) and user labels/folders. This clearly separates it from siblings like proton_create_folder and proton_list_emails.

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

Usage Guidelines5/5

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

Gives explicit guidance: use the returned 'path' values as the mailbox argument in other tools, and call it first when the mailbox layout is unknown. Both the when-to-use condition and the downstream consumption pattern are stated.

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

Deploy Server