system_get_selected_text

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

Annotations already cover the safe read-only profile, but the description adds valuable behavioral context: it avoids clipboard keystroke fallback and requires accessibility permissions. This helps an agent understand the method and auth needs beyond the structured 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 very short and front-loaded with the core purpose. Every fragment adds useful information: method constraint and permission requirement, with no wasted text.

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 the simple zero-parameter read operation, existing output schema, and rich annotations, the description is largely complete. It could explicitly route between this tool and clipboard_read, but the method exclusion provides enough context for correct selection.

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 tool takes zero parameters, so there is no parameter semantics to document in the description. The baseline for a zero-parameter tool is 4, and nothing in the description contradicts or adds parameter details.

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?

States a specific verb and resource: reading selected text from the focused Accessibility element. It also distinguishes itself from a clipboard-based sibling by explicitly saying it does not use clipboard keystroke fallback.

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 contrasting the method with clipboard fallback, but it does not explicitly state when to choose this tool over clipboard_read or what conditions must be met. No clear when/when-not guidance is present.

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