pebble-mcp

by dbonomo

Overview Schema Source Related Servers Discussions Admin

Python

Local

emu_stop

Shut down the running emulator, optionally wiping its storage to clear stale state and fix app launch issues.

Instructions

Shut down the running emulator; wipe=True also clears its storage.

Wiping is the fix for most emulator flakiness (apps not launching, stale state). Requires the pebble CLI on PATH.

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": "emu_stop"
  }
}

Input Schema

Name	Required	Description	Default
`wipe`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 2, 2026

TDQS

A4.5/5.0

Behavior4/5

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

No annotations are present, so the description carries the full burden. It discloses the main effect (shutdown), the wipe behavior (clears storage), and the CLI requirement. It could add what happens with unsaved state or error conditions, but for a simple stop tool this is adequate.

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 filler, front-loaded with the core action. Every sentence serves a purpose: the first states the primary function, the second explains the wipe option and the prerequisite.

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?

For a one-parameter stop tool, the description is complete: it covers the action, the optional flag, and the external dependency. It does not specify what happens if no emulator is running, but that is a minor gap given the simple scope.

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

Parameters5/5

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

The schema has only one boolean parameter, 'wipe', with zero coverage in the schema descriptions. The description fully explains the parameter: 'wipe=True also clears its storage' and adds why it matters (fixes flakiness). This compensates entirely for the low schema coverage.

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?

The description uses a specific verb+resource: 'Shut down the running emulator', immediately clarifying the tool's function. It also mentions the wipe option, which distinguishes it from sibling tools like emu_start and emu_screenshot.

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

Usage Guidelines4/5

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

Provides clear usage context: 'Wiping is the fix for most emulator flakiness' explains when to enable wipe. It also notes the prerequisite of the pebble CLI. However, it does not explicitly contrast with alternatives like emu_start or mention when not to use it.

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