Anthropic's current installation route uses desktop extensions for local MCP servers. Open Settings > Extensions, choose Browse extensions, install the approved extension, and complete its configuration. A custom extension can be installed from a .mcpb package through Advanced settings > Install Extension. Official local MCP setup
Configure the extension you actually installed
A local MCP server supplies tools that Claude can call. A Claude Skill supplies reusable instructions; installing a Skill does not create a missing connection to your filesystem or another service.
For a concrete setup check, suppose your organization provides an approved local document-search extension. Its configuration asks for a folder containing public product manuals. Choose that folder instead of granting a broader directory simply to make the first query work.
Use the extension's configuration interface for credentials or required paths. Follow its own instructions for prerequisites. A tool that connects to a separate service may need that service configured even when the extension package has installed successfully.
Do not paste a credential into the conversation as a substitute for a missing configuration field.
Inspect the tools before asking for work
Open the + menu in the Desktop conversation and select Connectors to inspect connected servers and their tools. Developer settings also show connection status and logs. If the extension is installed but tools remain unavailable, Anthropic recommends checking required fields and restarting Claude Desktop to refresh its extension registry. Save other work before restarting the app. Connection checks and troubleshooting
Use the result of that inspection to choose the next step:
| What you observe | What to check next |
|---|---|
| Extension is absent from Settings | Installation or organization policy |
| Extension is present with an incomplete field | Its configuration requirements |
| Server reports a connection error | The error and the extension's logs |
| Expected search tool is visible | A small permitted query and its returned source |
These are diagnostic decisions, not a claim that a particular extension has been tested here.
Make the first request easy to verify
For the illustrative manual-search extension, use a known document and a distinctive phrase:
Use the connected manual-search tool to find the document titled
"Pump inspection quick reference" in the configured manuals folder.
Find the section containing "inspection interval" and return the
filename, section heading, and supporting passage. If no matching
document is accessible, report that result. Do not answer from
general maintenance knowledge. Do not edit, move, or delete files.
Compare the returned passage with the original manual. If the tool runs but searches the wrong folder, correct the configured scope. If it returns the right file with no matching section, inspect the actual tool output before assuming the connection is broken.
Local desktop extensions and remote connectors can have different setup paths and availability. Keep this check inside Claude Desktop, where you installed the local extension. Once the intended tool is visible and the known passage matches, expand the request to the real document task.