Tool description

What Tool description means

Small wording changes can alter selection, making descriptions part of application behavior.

Where Tool description comes up on this site

• What is the agentic web? What it means for your websiteTools Sites and services now expose tools to agents directly through MCP servers, and a tool description is text a model reads as guidance.
• How to check an MCP server is safe before an agent connectsIf a sentence would sound odd read aloud to the user, it should not be in a tool description.
• How an AI agent should verify a website before it actsMost harm on the agentic web comes from a change nobody re-checked: a checkout that moved to a new host, a login that now points at a different provider, a tool description rewritten after approval (an MCP rug pull ).
• agents.md: AI agent instructions you may not have writtenWe kept the check rather than loosening it further, because the command forms are exactly what real suppression looks like: when we read every tool description in the official MCP Registry, four servers told the model to keep something from the user .
• Do AI agents stop before acting on a lookalike? We tested 4Some dangers are visible: a domain that swaps a letter, a tool description that says “do not tell the user”.

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.

OpenSearch description · traceparent · JSON Schema · protected-resource metadata · token audience · PKCE · refresh token · default scope request · tool poisoning · tool lockfile · MCP rug pull · tool shadowing · 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 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 description

What is Tool description?

Natural-language guidance telling a model when and why to use a tool.

Which area of the glossary does Tool description 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.

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