type_text

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

With no annotations, the description carries the full burden and adds one genuine behavioral constraint: '(printable ASCII)'. That usefully caps accepted input beyond the schema. However, it omits failure behavior, whether the field is cleared first, and permission/device requirements.

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?

A single tight sentence with the actionable resource front-loaded and no wasted words. It is efficient, though slightly under-specified rather than optimally informative.

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?

For a simple input-mutation tool with no annotations and no output schema, the definition is minimally adequate. It covers what the tool does and an input constraint, but leaves prerequisites (field focus) and error handling unaddressed given the absence of structured safety signals.

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 50% (serial is documented, text is not). The description partly compensates by characterizing the text parameter as printable ASCII, adding meaning beyond the schema, but says nothing about the 1000-char maxLength or the serial parameter's role.

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 specific verb+resource: 'Type text into the focused field'. The 'focused field' scope distinguishes it from tap/tap_element, but it never names those siblings or key_event explicitly, so sibling differentiation is only implied.

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 'focused field' softly implies a prerequisite (something must already be focused) but the description never states when to use this over key_event or tap_element, nor what to do if no field is focused. Usage is inferable but not explicit.

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