Send Text Input

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

Annotations already mark the tool as not read-only and not idempotent, and the description reinforces this while adding a useful behavioral detail not captured by the annotations: repeated calls append to the focused field. It also discloses the mutation target and the focus precondition. Minor credit is lost because some wording simply restates the annotation flags rather than adding entirely new behavioral context.

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?

Four sentences with no filler; every sentence earns its place: purpose/endpoint, precondition, mutation semantics, and guidance versus keypress. The core purpose is front-loaded in the first sentence.

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 two-parameter tool with no output schema, the description is complete: it states what the tool does, when it can be used, what side effects it has, and which alternative to use. The schema and annotations cover the remaining details, so nothing essential is missing.

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 description coverage is 100%: both 'text' and 'device' are already explained in the input schema. The description adds no new parameter-level detail, so the baseline score of 3 is appropriate since the schema carries the full parameter documentation burden.

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 ('Type') and resource ('a literal text string into whatever input field is currently focused'), explicitly names the ECP /input endpoint, and clearly distinguishes itself from keypress by noting it is the better alternative to sending characters as individual keys. An agent can confidently tell this tool apart from its siblings.

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 an explicit precondition ('Requires a text field to already be focused') and names the sibling tool to use first ('use keypress to navigate into one first'). It also tells the agent when to prefer this tool over keypress with a direct statement: 'Use this instead of sending characters as individual keypress keys.'

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