client_type

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

With no annotations provided, the description carries the full burden and does so thoroughly. It discloses that the tool takes the foreground, verifies it obtained focus before typing, refuses keystrokes if Windows denies focus, uses US-layout scancodes, rejects characters without scancodes by name before taking the screen, and exactly what submit/empty-text combinations do. It even explains the historical accident that made verification non-optional.

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 long, but every sentence adds essential behavioral or safety information for a tool that can steal focus from a human user. The core purpose is front-loaded, and the length is justified by the tool's risk profile and the need to prevent the exact failure mode described.

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 that there are no annotations, the description fully covers prerequisites (active window), side effects (foreground taken), safety checks, keyboard layout concerns, refusal behavior, submit semantics, and empty-text edge cases. An output schema exists, so the description need not explain return values. An agent has enough context to invoke the tool correctly and avoid the documented accident.

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 0%, so the description must explain both parameters. It specifies that text is typed as US-layout scancodes and that unscancodeable characters are refused by name. It also details submit ('presses Enter afterwards'), including the special case of submit=True with empty text sending only Enter, and the refusal of empty text without submit. This goes far beyond the bare schema.

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 precise verb and resource: 'Type into a CLIENT-SIDE INPUT FIELD -- a mod's PDA, terminal or form.' It clearly distinguishes itself from client_chat by explaining that chat is server-side and delivered without focus, while this tool exists for client-only fields that must be typed into like a person would.

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 says when not to use it: 'This is not chat. Chat is a server-side message and client_chat delivers it with no focus at all; use that unless the point of the test IS the typing.' It also explains the submit behavior to avoid needing a second foreground-taking tool, giving clear context for when submit is useful.

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