tool shadowing
Two MCP servers exposing tools with the same names, so an agent connected to both can call the wrong one, or a server copies a known publisher's tools to borrow its trust. Shadowing is detected by comparing tool lists across servers and across the servers one client connects to.
What tool shadowing does not show
A shared generic name such as search or fetch is not shadowing on its own.
Where tool shadowing comes up on this site
- How an AI agent should verify a website before acting on itOur guide on checking an MCP server before an agent connects covers tool poisoning , tool shadowing and pinning what you approved in a tool lockfile .
- MCP servers that ask for a login: what 1,366 request firstA correction to our own scan Our first pass at tool shadowing across the same registry flagged 11 servers as copying another publisher’s tools.
Terms this definition uses
Related terms in Agents and protocols
How autonomous agents plan, remember, call tools and talk to each other, including MCP and A2A, and where each step can go wrong.
protected-resource metadata · token audience · PKCE · refresh token · default scope request · tool poisoning · tool lockfile · MCP rug pull · MCP preflight · agent manifest · stapled verdict · verdict over DNS · agentic web · preflight · decision receipt · receipt header · action assurance · resolve answer · freshness window · AI agent · Agent loop · Planner · Executor · Agent memory · Working memory · Long-term memory · Episodic memory · Semantic memory · Agent orchestration · Multi-agent system · Agent handoff · Delegation · Tool result · Tool schema · Tool description · Tool selection · Tool permission · Human-in-the-loop · Human-on-the-loop · Approval gate · Agent sandbox · Agent identity · Agent authorization · Agent discovery · Capability negotiation · MCP server · MCP client · MCP host · MCP resource · MCP prompt · MCP tool · MCP transport · JSON-RPC · A2A protocol · A2A client · A2A server · Agent skill · Agent task · Agent artifact · WebMCP · A2A
Questions about tool shadowing
What is tool shadowing?
Two MCP servers exposing tools with the same names, so an agent connected to both can call the wrong one, or a server copies a known publisher's tools to borrow its trust. Shadowing is detected by comparing tool lists across servers and across the servers one client connects to.
What does tool shadowing not show or guarantee?
A shared generic name such as search or fetch is not shadowing on its own.
Which area of the glossary does tool shadowing belong to?
Agents and protocols: How autonomous agents plan, remember, call tools and talk to each other, including MCP and A2A, and where each step can go wrong.
← MCP rug pull · MCP preflight →
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