input_text

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

Annotations provide no readOnly/destructive warnings beyond defaults (readOnlyHint=false, destructiveHint=false), but the description does add useful behavioral context: it 'reports device context' and 'auto-detects and taps the send button' which implies two sequential actions. It doesn't disclose behavior when no element is found, focus failures, or typing speed/visibility limitations beyond what schema covers.

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?

Three sentences, all load-bearing. First sentence states core action, second covers the key option (submit), third covers the targeting mechanism. Zero filler or redundancy.

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?

A moderately complex tool (6 params, output schema present) with clear enough guidance. It covers primary action, optional submit behavior, and targeting alternatives. The output schema exists so return values are already documented. Missing context includes interplay with ui_tap_element or ui_wait_for_element, and behavior on validation failures, but overall adequate.

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% and schema descriptions are decent, but the description adds meaningful nuance: elementText is explained with concrete examples ('Full Name', 'City/Domicile'), and it clarifies the targeting options are alternatives to auto-focus. The 'device context' reporting aspect for serial is a useful addition beyond the schema's bare 'Device serial number'.

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?

Clear verb+resource: 'Type text into the input field.' Distinguishes from siblings by noting it also reports device context and supports submit and targeted field selection. This differentiates it from related tools like ui_smart_fill, form_fill, and key_event.

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 explains when submit=true is appropriate (auto-tap send for chat/messaging apps) and when to use targeted element selection instead of auto-focus. However, it doesn't explicitly state when to prefer input_text over helpers like ui_smart_fill or form_fill, or when auto-focus might fail.

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