Select by Polygon

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

The annotation readOnlyHint=true already covers the safety profile, so the description needs only to add behavioral context. It mentions window/crossing modes, but does not disclose whether the selection replaces or adds to the current selection, which would be useful. No contradiction with annotations.

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 concise sentence that front-loads the core purpose and comparison, with no unnecessary words or repetition of schema content.

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 full schema parameter descriptions, a readOnly annotation, and an output schema, the description is complete for this selection tool. It communicates the key distinction from rectangle selection and the two modes, which is sufficient for an agent to use it correctly.

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?

All parameters are fully described in the schema (100% coverage), so the description does not need to explain them. The description does not add any extra meaning beyond the schema's parameter descriptions, which is adequate given high coverage.

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 a specific verb (selection) and resource (polygon), and distinguishes from rectangle-based selection with 'rather than a rectangle.' This makes the tool's purpose immediately clear and differentiates it from sibling tools like selection_window.

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 phrase 'rather than a rectangle' provides clear context that this is for polygon-based selection, implying an alternative for rectangle selection. However, it does not explicitly name sibling tools or state when not to use it, so it falls short of full guidance.

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