exists

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

No annotations are provided, so the description carries the full behavioral burden and delivers nothing: it does not say whether the check is immediate or waiting, whether it throws or returns a boolean, or what happens on timeout. The 'timeout' parameter hints at a wait, but the description never confirms or explains that behavior.

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 short, but this is under-specification rather than conciseness — the one sentence spends its words on a tautology plus an unexplained '(alias)' marker instead of front-loading the actual check semantics.

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?

With no annotations, no output schema, and 0% parameter documentation, the description must carry everything and carries nothing. An agent cannot reliably invoke this tool correctly from what is given.

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 both parameters, and the description adds no meaning for 'selector' or 'timeout'. Neither the selector syntax nor the timeout unit/default is stated anywhere, leaving the agent to guess.

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 restates the name with a parenthetical '(alias)', which is closer to tautology than explanation. It never says what is being checked for existence (a DOM element? a file? a page?) or what the selector targets, so an agent cannot distinguish it from siblings like is_visible, count, or wait_for.

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?

No when-to-use guidance is given, and no alternative is named. The crowded sibling set (is_visible, count, wait_for, find) makes routing ambiguous, and the '(alias)' note implies a duplicate of another tool without saying which one or why to prefer either.

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