AndroJack-mcp

Android Testing Guide

android_testing_guide

Read-onlyIdempotent

Prevent incorrect Android test code by fetching official references for JUnit4, MockK, Turbine, Compose, Espresso, ViewModel, Room, Hilt, and the test pyramid before writing tests.

Instructions

Testing reference: unit tests (JUnit4, MockK, Turbine, coroutines-test), Compose UI tests, Espresso, ViewModel and Room tests, Hilt testing, test pyramid. Call before writing tests.

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": "android_testing_guide"
  }
}

Input Schema

Name	Required	Description	Default
`topic`	No	Testing topic. E.g. 'unit tests', 'compose testing', 'espresso', 'hilt testing', 'pyramid'. Leave empty to list all.
`refresh`	No	Resend content already sent in this session

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv2.1.0Oct 18, 2026

addedInput schema / properties / refresh

Added value: +{
+  "description": "Resend content already sent in this session",
+  "type": "boolean"
+}

First observedv1.7.1Jun 11, 2026

TDQS

A3.9/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the agent knows this is a safe, repeatable lookup with no side effects. The description adds the pre-test-writing trigger but says nothing about caching/deduplication behaviour, and the session-scoped 'refresh' semantics live only in the schema. Adequate against the annotation baseline, but not rich.

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: a front-loaded purpose statement followed by the invocation trigger. The parenthetical library names earn their space by signalling coverage depth, and there is no filler.

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 two-parameter, read-only lookup with no output schema, the description supplies the content domains and the call trigger, which is close to enough. The remaining gap is return shape and the purpose of `refresh` in cross-session reuse, but that is minor for a reference tool.

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?

Schema description coverage is 100%, so the baseline is 3, but the description goes beyond the schema's example values by naming topics the schema omits (ViewModel and Room tests, Compose UI tests, JUnit4/MockK/Turbine), which directly informs what strings are valid for `topic`. That is genuine added meaning for the primary parameter.

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 a specific resource (a testing reference) and enumerates the exact domains it covers — unit tests, Compose UI tests, Espresso, ViewModel/Room, Hilt, test pyramid — so an agent knows precisely what knowledge it returns. It stops short of explicitly differentiating itself from near-neighbours such as kotlin_best_practices or android_code_validator, which is the only thing keeping it off a 5.

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?

'Call before writing tests' is an explicit, actionable trigger condition, which is more than most reference tools offer. There are, however, no exclusions — nothing says when to reach for android_code_validator or kotlin_best_practices instead, so the routing guidance is one-sided.

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