tell-mcp-api

tell-mcp-api is a cursor rule for Cursor from ashishpatill/tell-proof. It costs 0 tokens per session (289 once invoked), scanned A, original, MIT.

A set of rules for keeping an MCP server and web API consistent. MCP is a standard connection that lets AI agents call tools, while an API is a programmatic interface used by software.

In plain words
What is it for?
It is for maintaining tool registration, authentication for diagnosis requests, install instructions, offline fallbacks, and local-only setup scripts.
Why use it?
It defines which tools are public, how failures should be reported, and which operations may or may not change a repository.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

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.

agentmods
npx agentmods add rules/ashishpatill/tell-proof/tell-mcp-api
Clone the repo
git clone --depth 1 https://github.com/ashishpatill/tell-proof

Made for: Cursor.

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 tell-mcp-api

README.md
[![agentmods](https://agentmods.dev/badge/rules/ashishpatill/tell-proof/tell-mcp-api.svg)](https://agentmods.dev/rules/ashishpatill/tell-proof/tell-mcp-api)
Your own site
<a href="https://agentmods.dev/rules/ashishpatill/tell-proof/tell-mcp-api"><img src="https://agentmods.dev/badge/rules/ashishpatill/tell-proof/tell-mcp-api.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 289 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00289
Opus 5 $0.00000 $0.00144
Sonnet 5 $0.00000 $0.00058
Haiku 4.5 $0.00000 $0.00029

Measured 5d ago against content hash 011b608555e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

tell-mcp-api 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.

.cursor/rules/tell-mcp-api.mdc · 18 lines

What it actually says

MCP and API rules

  • tell_capture, tell_diagnose, tell_redesign, tell_apply, matrix/proof/design/voice/install_info are the public Cursor surface.
  • Tool names are gated by @tell/schema MCP_TOOL_NAMES — keep skill docs and REGISTERED_MCP_TOOLS in sync.
  • tell_apply returns patch text and instructions only. It must never write to the user's repo.
  • Web /api/diagnose may use deterministic subprocess output; MCP tell_diagnose may add taste when keys exist.
  • GET /api/install-info and tell mcp install cursor are the Connect Agent source of truth.
  • When TELL_CAPTURE_API_TOKEN is set, diagnose requires Bearer / x-tell-capture-token.
  • All API failures should return plain-language state and preserve the offline report fallback.
  • /api/setup/* and repo-runner.ts execute cloned repo scripts and are local-dev only.
  • Keep .cursor/mcp.json registered as pnpm -F @tell/mcp start unless the package script changes.
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 · 18 lines · 0 tokens per session scan A 011b608555e1

Subscribe to this mod's changes

tell-mcp-api is a cursor rule published in the GitHub repository ashishpatill/tell-proof (1 stars, last pushed 10d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 289 tokens. 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.