Tool calling

Skills and tool calls

A selected skill contributes workflow rules, quality checks, and safety boundaries to the model context. When the active profile exposes a compatible tool, Hermes can then call it using that tool's registered schema.

request
  → load arcgis-rest-service-validator
  → inspect the connected tool schemas
  → call a public HTTP or ArcGIS metadata endpoint
  → validate count, paging, geometry, CRS, and fields
  → return evidence and limitations

Tool schemas come from the active profile

Hermes declares enabled tools to the model with their names, descriptions, and argument schemas. The model can call only the tools that are actually registered for that session. Results return as structured tool output before the final answer is written.

The GIS skill package does not register a GIS toolset. It adds procedural knowledge that can guide built-in web, browser, terminal, and file tools, or separately configured MCP servers and custom integrations.

A safe spatial lookup sequence

An address-to-zoning lookup is usually at least two operations:

1. Geocode the approved address to point geometry.
2. Query the zoning layer with that geometry and an ArcGIS spatial relationship.
3. Request only necessary output fields.
4. Validate result count, source, and spatial reference.
5. Report the district code, source URL, timestamp, and caveats.

The exact calls depend on the registered integration. If no compatible tool is available, the skill can still produce a validation plan and implementation commands without pretending execution occurred.

Write operations

For publishing, edits, database writes, or hosted-content changes, tool implementations should enforce least privilege, exact target verification, preview or diff output, approval tied to the final arguments, and a rollback path. Skill text is guidance; it is not a hard security boundary.