Calculate area of a polygon on Earth's surface.
| Name | Required | Description | Default |
|---|---|---|---|
| unit | No | Unit: km2 or mi2 | km2 |
| polygon | Yes | Polygon vertices as lat1,lon1;lat2,lon2;lat3,lon3... |
| Name | Required | Description | Default |
|---|---|---|---|
| area | Yes | ||
| unit | Yes | ||
| polygon_vertices | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description must carry behavioral disclosure. It does not mention algorithm (spherical/geodesic), limitations (self-intersecting polygons, antimeridian), or coordinate assumptions beyond lat,lon format.
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?
Single sentence is concise but lacks depth. While it fulfills basic purpose, it sacrifices important details like output format or usage notes. Not optimally structured for agent understanding.
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?
With output schema present, return values are covered, but description omits crucial context for polygon area calculation on Earth (e.g., closure requirement, coordinate order, algorithm). Incomplete for a geographic tool.
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 descriptions fully cover both parameters with format and unit options. Description adds no extra semantic value beyond schema, so baseline 3 is appropriate.
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?
Description clearly states 'calculate area of a polygon on Earth's surface', specifying the verb, resource, and geographic context. This distinguishes it from sibling tools like distance and centroid calculations.
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?
No guidance on when to use this tool versus alternatives (e.g., planar area tools, or when polygon might cross antimeridian). Missing context for appropriate usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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