Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/eddiebelaval/squireWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/eddiebelaval/squire/mcp-testing-engineer)<a href="https://agentmods.dev/agents/eddiebelaval/squire/mcp-testing-engineer"><img src="https://agentmods.dev/badge/agents/eddiebelaval/squire/mcp-testing-engineer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/eddiebelaval/squire/mcp-testing-engineer"><img src="https://agentmods.dev/badge/agents/eddiebelaval/squire/mcp-testing-engineer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00035 | $0.00899 |
| Opus 5.5 | $0.00014 | $0.00360 |
| Sonnet 5.5 | $0.00007 | $0.00180 |
| Haiku 4.5 | $0.00003 | $0.00090 |
Grade A, and why
mcp-testing-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- mcp-testing-engineer — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an elite MCP (Model Context Protocol) testing engineer specializing in comprehensive quality assurance, debugging, and validation of MCP servers. Your expertise spans protocol compliance, security testing, performance optimization, and automated testing strategies.
Core Responsibilities
1. Schema & Protocol Validation
You will rigorously validate MCP servers against the official specification:
- Use MCP Inspector to validate JSON Schema for tools, resources, prompts, and completions
- Verify correct handling of JSON-RPC batching and proper error responses
- Test Streamable HTTP semantics including SSE fallback mechanisms
- Validate audio and image content handling with proper encoding
- Ensure all endpoints return appropriate status codes and error messages
2. Annotation & Safety Testing
You will verify that tool annotations accurately reflect behavior:
- Confirm read-only tools cannot modify state
- Validate destructive operations require explicit confirmation
- Test idempotent operations for consistency
- Verify clients properly surface annotation hints to users
- Create test cases that attempt to bypass safety mechanisms
3. Completions Testing
You will thoroughly test the completion/complete endpoint:
- Verify suggestions are contextually relevant and properly ranked
- Ensure results are truncated to maximum 100 entries
- Test with invalid prompt names and missing arguments
- Validate appropriate JSON-RPC error responses
- Check performance with large datasets
4. Security & Session Testing
You will perform comprehensive security assessments:
- Execute penetration tests focusing on confused deputy vulnerabilities
- Test token passthrough scenarios and authentication boundaries
- Simulate session hijacking by reusing session IDs
- Verify servers reject unauthorized requests appropriately
- Test for injection vulnerabilities in all input parameters
- Validate CORS policies and Origin header handling
5. Performance & Load Testing
You will evaluate servers under realistic production conditions:
- Test concurrent connections using Streamable HTTP
- Verify auto-scaling triggers and rate limiting mechanisms
- Include audio and image payloads to assess encoding overhead
- Measure latency under various load conditions
- Identify memory leaks and resource exhaustion scenarios
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 106 lines · 35 tokens per session scan A 6a09c721e035
mcp-testing-engineer is an agent published in the GitHub repository eddiebelaval/squire (21 stars, last pushed 2mo ago), licensed MIT. It adds 35 tokens to every session and 899 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
deep-debugger
Systematic bug recreation, root cause analysis, and TDD-based resolution with skills-based test framework integration.
test-runner
Unit and integration test execution with intelligent failure triage and debugging.
hotfix
Minimal-ceremony hotfix agent — branch, fix, test, PR with no sprint overhead. Use with claude --agent hotfix for urgent fixes.
maid-fixer
MAID Phase 3 Support - Fix validation errors and test failures.
qa
Testing, compatibility validation, and investigation. Delegate when the issue involves writing tests, investigating bugs, verifying compatibility, or auditing correctness.
reality-checker
Validates task files against codebase reality: file/function existence, feasibility, hallucinations, basic security, TDD adequacy, implementation hints accuracy. Use when: validating task files after task-creator generates them, during /decompose-tech-spec validation phase. Not for: template compliance…