pebble-mcp

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store_download_pbw

Download a Pebble app's latest release .pbw to a specified directory and get its path, size, and version. Uses safety checks to avoid path traversal and invalid downloads, ready for installation or emulator use.

Instructions

Download an app's latest-release .pbw to dest_dir.

Creates dest_dir if needed, writes the file, and returns its path and byte size (plus the app title and version). The on-disk filename is derived from the (untrusted) appstore response but always sanitized to a single basename inside dest_dir — a hostile id/version cannot traverse out. Refuses with a clear error if: the app has no published .pbw; dest_dir exists as a non-directory; the body is empty (0 bytes); or the body exceeds a 32 MiB safety cap (real .pbw files are well under a megabyte). Sends the polite pebble-mcp User-Agent. This feeds the install/emulator flow — hand the returned path to a Tier 3 install tool.

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": {
      "app_id": "<app_id>",
      "dest_dir": "<dest_dir>"
    },
    "name": "store_download_pbw"
  }
}

Input Schema

Name	Required	Description	Default
`app_id`	Yes
`dest_dir`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 2, 2026

TDQS

A4.7/5.0

Behavior5/5

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

With no annotations, the description fully discloses side effects: it creates dest_dir, writes the file, sanitizes filenames to prevent traversal, enforces a 32 MiB cap, and sends a User-Agent. Error conditions (no published .pbw, non-directory dest_dir, empty body, oversize body) are enumerated, providing comprehensive behavioral transparency.

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?

The description is front-loaded with the main action and then adds concise, high-value details about side effects, safety, and return value. Every sentence earns its place; no filler or repetition.

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?

For a tool with no annotations and a sparse schema, the description is remarkably complete: it covers purpose, side effects, error handling, security behavior, return values, and downstream usage. The existence of an output schema allows it to omit detailed return formatting, but it still mentions key return fields.

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?

The input schema has 0% coverage, but the description uses both parameters in context: 'app_id' identifies the app and 'dest_dir' is the destination directory that gets created if needed. This provides enough meaning for an agent to understand their roles, though it does not explicitly define acceptable formats or sources for app_id.

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 opens with a specific verb–resource pair: 'Download an app's latest-release .pbw to dest_dir.' This clearly distinguishes it from sibling tools like store_search or store_app, which likely handle metadata. The purpose is unambiguous.

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?

The description states that this feeds the install/emulator flow and instructs passing the returned path to a Tier 3 install tool, giving clear usage context. However, it does not explicitly name alternative tools or state when not to use this tool, only implying it via the flow description.

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