android_input_text

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

The description adds context about operating on the focused field, which goes beyond the annotations. It implies a destructive replacement (consistent with destructiveHint=true). However, it does not specify whether 'replace' means replacing the entire field content or only a selection, and it does not discuss failure modes or side effects beyond the focus requirement.

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 two short, direct sentences with no unnecessary words or redundancy. It conveys the essential information efficiently, making it highly concise and well-structured.

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?

The description covers the main prerequisite (focus) and the core action, but lacks details about edge cases such as whether the text replaces the entire field or only selected text, what happens if no field is focused, or any error conditions. Given the absence of an output schema, the description is adequate but not fully comprehensive for an agent to handle all scenarios confidently.

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 sole parameter 'text' is not described in the schema, but the tool description implicitly clarifies it as the replacement text. The meaning is clear from the context of 'Replace text' and the parameter name. This effectively compensates for the 0% schema coverage, though it is not explicit about the parameter's intended use.

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 the action ('Replace text') and the target ('currently focused editable field'). It implies a specific resource and operation, making the tool's purpose unambiguous. However, it does not explicitly differentiate from sibling tools like android_ui_set_text, so it loses one point for not naming alternatives.

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 a prerequisite ('Focus the intended field first'), which gives some usage guidance. However, it does not explicitly address when to choose this tool over alternatives such as android_ui_set_text, nor does it mention conditions like field visibility or editability beyond what is implied. Guidance is present but not comprehensive.

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