calculate_spherical_polygon_area

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

With no annotations, the description carries the burden of behavioral disclosure. It provides useful behavior beyond the schema by specifying the geodesic method, the output units, and the exact cost of 0.015 USDC on Base L2. It does not mention error behavior or precise precision limits, but the core computation behavior is transparent.

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 one efficient sentence that front-loads the primary behavior and appends the cost as a terse, relevant note. Every element earns its place, and there is no redundant restating of the tool name or schema.

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?

The input schema is generic, there are no annotations, and there is no output schema, so the description must compensate. It gives the high-level input type and the output units, but an agent still lacks a concrete payload format/example and a clear return contract, which matters for a paid tool execution.

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?

The schema only describes payload as a generic 'Input parameters or JSON string payload.' The description adds key meaning by specifying that the payload represents 'latitude/longitude boundary polygons.' It still does not spell out the exact JSON structure, coordinate order, or units expected, so it falls short of a 5.

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 states a specific verb and resource: 'Computes geodesic surface area (km² / acres) of arbitrary latitude/longitude boundary polygons.' The phrase 'without planar distortions' also distinguishes it from planar area-calculation tools and area-related siblings like calculate_bounding_box_3d.

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 clearly identifies the intended use case: latitude/longitude boundary polygons that need geodesic rather than planar area. It implies not to use it for projected/flat geometry, but it does not explicitly name alternatives or state when not to use it.

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