session_input

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

There are no meaningful annotations (only a title), so the description carries the behavioral burden. It discloses the action and target element type, but does not state whether typing replaces existing text, appends to it, requires a visible/enabled element, or waits for readiness. This is a gap for an input-action tool.

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 sentence with no filler. The core action, target, and index source are all front-loaded in a compact, easily parseable format.

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 three-parameter tool with no output schema, the description covers the essential invocation path: obtain an index from session_state, then type text into that element. It omits deeper behavioral details like overwrite semantics or waiting behavior, but these are not fully necessary for a basic agent to call it successfully.

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 all three parameters already have descriptions. The description adds slight value by linking the index to session_state output and narrowing the target to input/textarea elements, but it does not substantially improve on the schema's parameter explanations.

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 names a specific action ('Type text'), a specific target ('input/textarea element'), and a precise element-identification method ('by its index from session_state output'). This clearly differentiates it from siblings like session_click or session_scroll.

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 gives clear context: use this tool to type text into an element identified by an index obtained from session_state output. It does not explicitly state when not to use it or name alternative tools, but the intended usage scenario is unambiguous.

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