Type text

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

Description goes beyond readOnly/destructive hints by describing append-at-caret behavior, the focus requirement, and support for contenteditable/rich-text/canvas widgets. It doesn't contradict annotations; readOnlyHint=false and destructiveHint=false are consistent with focused text-typing mutation.

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 purposeful sentences: definition, behavioral constraint, and usage guidance. No filler; every sentence adds operational value without being verbose.

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 tool's simple two-parameter schema, existing output schema, and annotations, the description covers focus prerequisite, append semantics, widget compatibility, and alternative tool selection. This is complete for an agent to select and invoke correctly.

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 input schema already fully describes both parameters, including the default for submit_key and the one-character-at-a-time behavior. The description adds no new parameter-level detail, so schema coverage earns the baseline 3.

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 opens with a specific verb and resource ('Type text into whatever element currently has focus') and immediately clarifies scope (appends at caret, needs pre-existing focus). It distinguishes itself from sibling fill by naming it as an alternative and setting different use cases.

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?

Explicitly states when to prefer fill ('ordinary form filling') and when to use type_text ('add to existing content, or widgets that only react to raw key events'). It also tells the agent that a prior click/focus step is required, or to use fill which needs no separate focus step.

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