apple_tv_set_text

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

Annotations already declare it non-read-only, idempotent and non-destructive; the description adds genuine context beyond that by stating the virtual-keyboard precondition and that an empty string clears the field — a behavior an agent could otherwise trigger by accident. It does not say what happens if no keyboard is focused (error vs no-op).

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?

Two short sentences, front-loaded with the action, followed by the precondition and the edge case. No filler.

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?

An output schema exists, so return values need not be described, and the mutation semantics, precondition and empty-string behavior are covered. The only real gap is failure behavior when the precondition is unmet.

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 coverage is 100% for the single parameter, and the property description already says 'Empty string clears it.' The description restates that same fact rather than adding format or length constraints, so the schema is doing the work.

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 ('Replace text in a focused Apple TV text field'), making it immediately distinguishable from the press/seek/playback siblings. An agent can tell this is the text-entry tool without reading any schema.

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?

Gives a clear precondition for use ('Requires an active virtual keyboard') and the edge-case semantic for an empty string. It does not name an alternative (e.g. apple_tv_press for individual key presses), so it stops short of full routing guidance.

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