QGIS MCP Server

Add Features

add_features

Destructive

Add features with attributes and WKT geometries to a vector layer, with optional CRS reprojection and validation against the layer's geometry type.

Instructions

Add features to a vector layer. Each feature: {attributes: {field: value}, geometry_wkt: 'POINT(1 2)'}. geometry_wkt is in the layer's CRS, or in crs when given (it is then reprojected). A geometry type the layer cannot hold is refused; invalid geometry or 2D on a Z layer comes back in warnings. Returns count of added features.

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": {
      "layer_id": "<layer_id>",
      "features": "<features>"
    },
    "name": "add_features"
  }
}

Input Schema

Name	Required	Description	Default
`crs`	No
`features`	Yes
`layer_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 13, 2026

TDQS

A4.1/5.0

Behavior5/5

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

The description goes well beyond the annotations by explaining CRS handling and reprojection, refusal of unsupported geometry types, warnings for invalid geometry or 2D-on-Z mismatches, and the return value. These are specific behavioral details that an agent needs to anticipate outcomes correctly. No contradiction with the destructiveHint annotation is present.

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

Conciseness5/5

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

The description is compact and efficient, with every sentence providing necessary information. It front-loads the primary purpose, then delivers the feature format, CRS behavior, failure/warning cases, and return value without any filler.

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

Completeness4/5

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

For a mutation tool with no output schema and minimal annotations, the description is largely complete: it covers input format, CRS semantics, validation failures, and the return count. It does not mention whether an editing session is required or how it interacts with sibling editing tools, which would be useful but is not strictly necessary for invoking the tool correctly.

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

Parameters5/5

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

With schema description coverage at 0%, the description carries the entire burden of explaining parameters. It details the exact structure of each feature entry, including attributes and geometry_wkt, and clarifies the meaning of the crs parameter and its reprojection behavior. This adds essential meaning beyond the raw schema.

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

Purpose4/5

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

The description states a specific verb and resource: 'Add features to a vector layer.' It is clear about what the tool does, but it does not explicitly distinguish itself from sibling tools like update_features or delete_features. The behavior of adding rather than modifying or removing is evident, though no comparison is made.

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 given on when to use this tool versus alternatives. There is no mention of editing sessions, prerequisites, or cases where update_features or delete_features would be more appropriate. The purpose implies usage, but the description does not provide explicit context or exclusions.

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

Deploy Server