Type

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

With no annotations, the description carries the full behavioral burden, and it only partially delivers: it explains the stealth/keystroke and index/tap-then-type behaviors. It says nothing about what 'clear' does to existing field content, how 'device' selects a target, or any permission/latency characteristics of this input-mutating operation.

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?

It is tight and front-loaded into a single sentence with no filler, which is good. But the dense parenthetical jargon and clipped clauses ('get_state element', 'mobilerun-core') trade clarity for brevity, making it harder to parse than a cleaner phrasing would be.

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?

An output schema exists, so return values need not be described. But for a 6-parameter mutation tool with zero annotation coverage and 0% schema description coverage, the agent is left without enough to call it confidently, and half the parameters remain undocumented anywhere.

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% across 6 parameters, so the description must compensate and does so only partly. It clarifies index, stealth, and wpm, but leaves text, clear, and device completely unexplained, and even the covered ones lack format detail.

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 gives a clear verb+resource ('Type text') and tags the backend (mobilerun), so the basic action is understood. However, it does not distinguish itself from close siblings such as type_text, tap_text, or key, and the '(mobilerun)' qualifier is opaque jargon rather than a real differentiator.

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?

It implicitly tells the agent when the 'index' and 'stealth' behaviors matter ('index taps that get_state element first', 'stealth=true types key by key like a person'), which is usable context. But there is no explicit statement of when to prefer this tool over the sibling type_text, and no prerequisites are given.

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