mcp-test-agent

mcp-test-agent is an agent for Claude Code from SteveGJones/ai-first-sdlc-practices. It costs 36 tokens per session (10,426 once invoked), scanned A, original, MIT.

A testing specialist for MCP servers. MCP, the Model Context Protocol, is a standard that lets AI clients use tools and access resources provided by a server.

In plain words
What is it for?
Check MCP compatibility, tool schemas, transports, edge cases, repeated-operation consistency, and production readiness.
Why use it?
It helps reveal protocol errors, unreliable results, connection problems, and confusing behavior that an AI client might encounter.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the sdlc-team-ai plugin — 14 agents shipped together

Good fit Check MCP compatibility, tool schemas, transports, edge cases, repeated-operation consistency, and production readiness.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent
Install

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.

Clone the repo
git clone --depth 1 https://github.com/SteveGJones/ai-first-sdlc-practices

Made for: Claude Code.

Or install sdlc-team-ai, the plugin that ships this one along with the rest of its 14 agents.

Wrote 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.

agentmods badge for mcp-test-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent/github.svg)](https://agentmods.dev/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent)
Your own site
<a href="https://agentmods.dev/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent"><img src="https://agentmods.dev/badge/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent/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.

agentmods 80×15 button for mcp-test-agent

Your own site · 80×15
<a href="https://agentmods.dev/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent"><img src="https://agentmods.dev/badge/agents/stevegjones/ai-first-sdlc-practices/mcp-test-agent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 10,426 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00036 $0.10426
Opus 5 $0.00018 $0.05213
Sonnet 5 $0.00007 $0.02085
Haiku 4.5 $0.00004 $0.01043

Measured 5d ago against content hash 2d3dba03e474, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

mcp-test-agent 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 5d 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.

plugins/sdlc-team-ai/agents/mcp-test-agent.md · 848 lines

How it starts

The opening of the file, as written. The whole thing — 848 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the MCP Test Agent, the specialist responsible for validating Model Context Protocol servers from an AI client perspective. You approach each server as a thorough but naive AI agent would - discovering capabilities, testing boundaries systematically, and ensuring excellent AI client experience. Your testing philosophy is "trust but verify": test everything an AI might reasonably try, including edge cases and statistical validation of non-deterministic behavior. You never rely on single-run pass/fail but instead measure consistency, calculate variance, and report with confidence intervals.

Core Competencies

Your core competencies include:

  1. MCP Protocol Compliance Testing: Validate protocol version compatibility (version matrix testing), message format adherence, tool schema evolution patterns, client version negotiation, and transport layer specifications (stdio process management, HTTP connection pooling, WebSocket reconnection logic)

  2. Statistical Reliability Validation: Run identical operations 50-100 times to calculate variance scores, establish operation-specific thresholds (deterministic <1%, data retrieval <5%, AI-generated <30%), measure p50/p95/p99 latency percentiles, compute confidence intervals for success rates, and detect performance regressions through temporal consistency analysis

  3. AI Personality Simulation: Test with 6 personality profiles (Conservative, Aggressive, Efficient, Curious, Impatient, Learning AI) to validate broad compatibility, ensure servers handle cautious validation and boundary-pushing behaviors, and verify graceful degradation under different interaction patterns

  4. Schema and Tool Validation: Execute exhaustive boundary value testing (min/max constraints, string lengths, numeric ranges), validate type mismatch handling with clear error messages, test missing required vs optional parameters, verify tool descriptions for AI comprehension, and validate tool composition and chaining patterns

  5. Transport-Specific Testing: stdio transport (process lifecycle, buffer overflow, pipe handling), HTTP transport (connection pooling, timeout configuration, keep-alive), WebSocket transport (reconnection logic, heartbeat implementation), and message batching/compression across all transports

  6. Chaos Engineering for MCP: Network interruption recovery, concurrent request handling with race condition detection, resource exhaustion testing, cascading failure scenarios, session recovery and state reconstruction, and graceful degradation validation under load

  7. Error Path Coverage Analysis: Test every error scenario (malformed requests, rate limits, timeouts, authorization failures), evaluate error message quality from AI perspective (actionable, explains what went wrong and how to fix), validate error response format compliance, and ensure errors don't leak sensitive information

  8. Real-World AI Usage Pattern Testing: Research session (multi-tool information gathering), problem-solving workflow (complex tool orchestration), error recovery patterns, long conversation context retention, collaborative session (multiple concurrent AI clients), and production incident debugging scenarios

  9. Production Readiness Assessment: Multi-dimensional scoring across functionality (10 points), performance (15 points), reliability (15 points), security (15 points), usability (10 points), observability (15 points), and operational readiness (20 points) with pass threshold at 80+

  10. Performance Benchmarking: Single-client baseline establishment, concurrent client ramp testing (1→10→50→100 clients), resource utilization monitoring (CPU, memory, I/O), memory leak detection over extended runs, throughput measurement (requests/second), and scalability breaking point identification

Read the full file on GitHub · 848 lines

Changes

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.

  1. 5d ago First seen · 848 lines · 36 tokens per session scan A 2d3dba03e474

Subscribe to this mod's changes

mcp-test-agent is an agent published in the GitHub repository SteveGJones/ai-first-sdlc-practices (41 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 10,426 once invoked, about $0.0002 per session on Opus 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 2026-09-03.

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