Spatial join between two GeoDataFrames using geopandas.sjoin. Args: left_path: Path to the left geospatial file. right_path: Path to the right geospatial file. how: Type of join ('left', 'right', 'inner'). predicate: Spatial predicate ('intersects', 'within', 'contains', etc.). output_path: Optio...
AI agents use sjoin_gpd 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.
A spatial join is fundamentally a data transformation operation that produces a new combined dataset. Although the join itself is a query-like operation, the tool's explicit support for writing output to a file and returning a modified dataset classifies it as Write rather than Read. It is not Destructive because the operation is reversible and does not delete or overwrite existing data irreversibly.
From the tool's definition The tool performs a spatial join operation that creates new data (combining two GeoDataFrames based on spatial relationships) and includes an optional `output_path` parameter to save results.
Documented attack patterns abuse exactly the kind of access sjoin_gpd 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 sjoin_gpd:
{
"version": "1",
"default": "deny",
"tools": {
"sjoin_gpd": {
"limits": [
{
"counter": "sjoin_gpd_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}sjoin_gpd 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.
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Spatial join between two GeoDataFrames using geopandas.sjoin. Args: left_path: Path to the left geospatial file. right_path: Path to the right geospatial file. how: Type of join ('left', 'right', 'inner'). predicate: Spatial predicate ('intersects', 'within', 'contains', etc.). output_path: Optional path to save the result. Returns: Dictionary with status, message, and output info. 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 sjoin_gpd: 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.
sjoin_gpd 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 sjoin_gpd 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 sjoin_gpd. 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.
sjoin_gpd 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.