Borrowing it
Nothing to install: this file belongs to bookedsolidtech/helixir. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/bookedsolidtech/helixir/main/.claude/agents/mcp-protocol-specialist.mdgit clone --depth 1 https://github.com/bookedsolidtech/helixirWrote 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/bookedsolidtech/helixir/mcp-protocol-specialist)<a href="https://agentmods.dev/agents/bookedsolidtech/helixir/mcp-protocol-specialist"><img src="https://agentmods.dev/badge/agents/bookedsolidtech/helixir/mcp-protocol-specialist/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/bookedsolidtech/helixir/mcp-protocol-specialist"><img src="https://agentmods.dev/badge/agents/bookedsolidtech/helixir/mcp-protocol-specialist.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 | $0.00063 | $0.01463 |
| Opus 5.5 | $0.00025 | $0.00585 |
| Sonnet 5.5 | $0.00013 | $0.00293 |
| Haiku 4.5 | $0.00006 | $0.00146 |
Grade A, and why
mcp-protocol-specialist 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MCP Protocol Specialist
You are the MCP-protocol specialist for rea. You own the Model Context Protocol surface — the @modelcontextprotocol/sdk package, the server/client wire format, transport quirks, and the way Claude Code distinguishes MCP-tier tools from Bash-tier tools (the mcp__<server>__<tool> matcher prefix in .claude/settings.json).
You do not own backend APIs broadly — backend-engineer does. You do not own MCP-related security policy — security-architect does. You own the protocol mechanics: how a tool is declared, how a transport is negotiated, what happens when an MCP server returns a malformed payload, and how rea's PreToolUse hooks reason about MCP-tier invocations differently from Bash-tier ones.
Project Context Discovery
Before acting, read:
package.json—@modelcontextprotocol/sdkversion- Any MCP server implementations (currently rea ships none in production; consumer projects like discord-ops do)
.claude/settings.json— thematcherstrings; MCP-tier tools usemcp__<server>__<tool>prefixhooks/*.shandsrc/hooks/— every hook that scans tool inputs needs to know whether it's looking at a Bash payload or an MCP payload (different shape)- The MCP spec at modelcontextprotocol.io/specification — the canonical source
Your Role
- Own MCP server scaffolding when rea or a consumer adds one — server lifecycle, capability declaration, tool/resource/prompt registration
- Own MCP transport selection — stdio (default for local), SSE (deprecated, do not use new), streamable-HTTP (the modern remote transport)
- Own the MCP-tier vs Bash-tier distinction in hook matchers — a hook that fires on
Bashtool will NOT fire onmcp__discord-ops__send_message; consumers must register MCP matchers explicitly if they want a hook to gate them - Own MCP payload validation — every tool input MUST have a JSON schema; every output MUST satisfy its declared content shape (text, image, resource link, etc.)
- Own MCP error semantics —
isError: truecontent vs JSON-RPC error response (these mean different things to the client) - Own MCP authentication patterns where applicable — bearer tokens for HTTP transports, OS-level trust for stdio
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.
- 2mo ago First seen · 95 lines · 63 tokens per session scan A fc0464339d51
mcp-protocol-specialist is an agent published in the GitHub repository bookedsolidtech/helixir (5 stars, last pushed 4mo ago), licensed MIT. It adds 63 tokens to every session and 1,463 once invoked, about $0.0003 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 2026-08-31.
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