GIS MCP Server

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

No annotations are provided, so the description carries full burden. It mentions the merge type and that geometry from the left file is preserved, but lacks details on permissions, error handling, file format requirements, or output behavior. For a tool with no annotations and multiple parameters, this is insufficient.

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

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

The description is front-loaded with the core purpose but includes a detailed parameter list that doesn't align with the schema, making it somewhat cluttered. It's moderately efficient but could be streamlined to avoid parameter discrepancies.

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

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

Given no annotations, 0% schema coverage, and an output schema present, the description partially covers the tool's purpose and parameters but fails to fully explain behavioral aspects or resolve schema mismatches. It's minimally adequate but leaves gaps in understanding the tool's full context.

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

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

Schema description coverage is 0%, with 3 parameters in the schema (shapefile1_path, shapefile2_path, output_path) but the description lists 7 parameters (e.g., left_shapefile_path, how, on). This mismatch and incomplete coverage means the description doesn't adequately compensate for the schema gap, adding confusion rather than clarity.

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

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

The description clearly states the tool 'merges two shapefiles based on common attribute columns' and specifies it's a 'database-style join, not a spatial join.' This distinguishes it from spatial join tools like sjoin_gpd. However, it doesn't explicitly differentiate from other non-spatial merge operations in the sibling list, keeping it from a perfect score.

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

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

The description implies usage by specifying it's for merging shapefiles with attribute-based joins, not spatial joins. It doesn't provide explicit when-to-use guidance versus alternatives like overlay_gpd or other sibling tools, nor does it mention prerequisites or exclusions.

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