Select by Polygon

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds the window/crossing distinction, which is useful behavioral context, but does not go deeper into edge cases or state effects. With annotations covering safety, this is adequate but not rich.

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 a single, compact sentence with no filler. It front-loads the core concept (polygon selection) and immediately distinguishes it from rectangle selection, earning its place efficiently.

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?

For a selection tool with a readOnly hint, full schema coverage, and an output schema, the description is sufficiently complete. It conveys the key differentiator and behavior. A small gap is that it does not explicitly state that the polygon must have at least 3 points, but this is covered in the schema.

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 100%, so the schema already documents all parameters clearly. The description does not add additional parameter-level semantics beyond what the schema provides, so the baseline score of 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?

The description clearly indicates this tool performs a selection operation using a polygon, and contrasts it with rectangle-based selection. It is clear about the resource being selected, though it does not explicitly name sibling tools like selection_window or selection_filter for differentiation.

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 provides clear context: use this tool when selection should be based on a polygon rather than a rectangle. It does not explicitly state when not to use it or name alternatives, but the polygon-versus-rectangle framing gives sufficient guidance for common cases.

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