Tool
A single callable operation an agent can invoke through a skill.
A tool is a single callable operation, like searching tickets, creating an invoice or reading a row. It has a name, a description and a schema for its arguments.
Tools are what make an agent act instead of talk. Everything else in Skilder exists to put the right ones in front of it at the right moment.
How it relates
Every tool comes from one MCP server, which is what you install. Skilder discovers the server's tools and lists them on the Tools page of Capabilities.
A tool reaches an agent through a skill. Selecting it in a skill is what makes it callable, and only by the roles that carry the skill.
An agent connected to Skilder never sees your tools in its own tool list. It sees a handful of Skilder tools, learns a role, and calls the tools that role unlocked by name. That is what keeps a workspace with three hundred tools usable: the agent's context holds what its role unlocked, not the catalog.
Calls travel over two channels, and the upstream server decides which. A tool the server declares read-only goes to the read channel. Everything else is treated as write-capable, including anything left undeclared.
What it contains
| Part | What it does |
|---|---|
| Name | What the agent calls, exactly as the server declares it. |
| Description and input schema | What the agent reads to call it correctly. |
| Server | The MCP server that provides it. |
| Status | Enabled or Disabled. Disabling a tool removes it from the agent catalog and leaves it listed for you. |
What it is not
A tool is not something you write in Skilder. You install the server that provides it, then choose which of its tools your skills use. To automate something no server offers, write a script in a skill instead.
Next
- Build a skill, to connect a tool.