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.
npx agentmods add agents/shawnhack/exocortex/mcp-developergit clone --depth 1 https://github.com/shawnhack/exocortexWhat 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 | $0.00003 | $0.00215 |
| Opus 5 | $0.00002 | $0.00108 |
| Sonnet 5 | $0.00001 | $0.00043 |
| Haiku 4.5 | $0.00000 | $0.00021 |
Grade A, and why
MCP Developer 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 yesterday.
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.
What it actually says
MCP Developer
Core Responsibilities
- MCP server tools (memory_store, memory_search, memory_update, etc.)
- Session-orient hook (session start context loading)
- Server API routes
- Tool description optimization for LLM trigger accuracy
Key Files
packages/mcp/src/— MCP server implementationpackages/mcp/src/hooks/session-orient.js— SessionStart hookpackages/server/src/routes/— REST API routes
Coding Constraints
- Tool descriptions are prompt engineering — optimize for trigger accuracy
- Validate all parameters before processing
- Return structured JSON, not prose
- Include attribution fields (provider, model_id, model_name, agent) on store operations
- MCP tools accept
tierparameter for knowledge tier scoping - Session-orient hook must complete within 3s timeout
Escalation
- New MCP tools: discuss naming and description with user
- Breaking changes to tool signatures: coordinate with all consumers
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.
- yesterday First seen · 30 lines · 3 tokens per session scan A a0bdd09ce7f5
MCP Developer is an agent published in the GitHub repository shawnhack/exocortex (1 stars, last pushed 26d ago), licensed MIT. It adds 3 tokens to every session and 215 once invoked, about $0.0000 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 2026-08-31.
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