Create a k-nearest neighbors spatial weights (W) object from point data. - data_path: path to point shapefile or GeoPackage - k: number of nearest neighbors - id_field: optional attribute name to use as observation IDs
AI agents use knn_weights to create or update resources in GIS MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GIS MCP Server environment.
This tool performs a computational analysis operation that creates/generates new data (a spatial weights matrix object). It does not retrieve existing data (Read), execute arbitrary code or external operations (Execute), delete or overwrite data irreversibly (Destructive), or involve financial transactions (Financial).
From the tool's definition Tool creates a spatial weights (W) object from input data. The description explicitly states 'Create a k-nearest neighbors spatial weights (W) object', which is a data generation/creation operation.
Documented attack patterns abuse exactly the kind of access knn_weights gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GIS MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for knn_weights:
{
"version": "1",
"default": "deny",
"tools": {
"knn_weights": {
"limits": [
{
"counter": "knn_weights_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}knn_weights stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Create a k-nearest neighbors spatial weights (W) object from point data. - data_path: path to point shapefile or GeoPackage - k: number of nearest neighbors - id_field: optional attribute name to use as observation IDs. It is categorised as a Write tool in the GIS MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the GIS MCP Server MCP server in PolicyLayer and add a rule for knn_weights: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches GIS MCP Server. Nothing to install.
knn_weights is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the knn_weights rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for knn_weights. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
knn_weights is provided by the GIS MCP Server MCP server (mahdin75/gis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from GIS MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
98 GIS MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.