Microsoft Fabric MCP Server

fabric_load_lakehouse_table

Load data from a file or folder in OneLake into a Delta table. Supports CSV, Parquet, overwrite or append modes.

Instructions

Load a file/folder in OneLake into a Delta table (long-running).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "lakehouseId": "<lakehouseId>",
      "tableName": "<tableName>",
      "relativePath": "<relativePath>",
      "pathType": "<pathType>",
      "mode": "<mode>"
    },
    "name": "fabric_load_lakehouse_table"
  }
}

Input Schema

Name	Required	Description
`lakehouseId`	Yes	Lakehouse ID
`tableName`	Yes	Target table name
`relativePath`	Yes	Source path under the lakehouse, e.g. "Files/data/sales.csv"
`pathType`	Yes	Whether the source is a file or folder
`mode`	Yes	Load mode
`format`	No	Source format (default inferred)
`recursive`	No	Recurse folders
`workspace`	No	Workspace ID (defaults to FABRIC_DEFAULT_WORKSPACE)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 18, 2026

TDQS

B3.1/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries full responsibility. It only mentions 'long-running', omitting critical behaviors like the nature of the load (append/overwrite), whether it can be canceled, or error handling. The description adds minimal value beyond the annotated (empty) state.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise at one sentence with no fluff. However, it could be slightly expanded to include usage guidelines without losing brevity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (8 parameters, enums, long-running nature) and lack of output schema, the description is insufficient. It fails to explain the overall process, prerequisites, or what happens after invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the description need not add param details. It adds no additional meaning beyond what the schema already provides, meeting the baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Load'), the resource ('file/folder in OneLake into a Delta table'), and a key characteristic ('long-running'), effectively distinguishing it from sibling tools like listing or creation operations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives, nor any prerequisites or conditions for invocation. The agent is left without decision support.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server