Tool description
Natural-language guidance telling a model when and why to use a tool.
What Tool description means
Small wording changes can alter selection, making descriptions part of application behavior.
Where Tool description comes up on this site
- The agentic web for site owners: permission, delivery, identity and toolsA tool description is text a model reads as guidance.
- How to check an MCP server before an AI agent connects to itIf 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 acting on itWhat changed Most 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 ).
- MCP servers that ask for a login: what 1,366 request firstTwo rules now apply before anything is published: both homepages are read and must show no shared operator, and a tool description published word for word by three or more publishers counts as a template, not as a copy.
- 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.
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.
← Tool schema · Tool selection →
See it in the full glossary · 731 terms across 19 areas.