Query the League client DOM

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

With no annotations provided, the description bears full disclosure burden. It reveals a key prerequisite (Pengu Loader's remote debugging port), describes the output format (tag, id, className, trimmed text, plus requested properties), and names a failure path. It doesn't explicitly say the operation is read-only, but querySelector semantics imply that.

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?

Two efficient sentences with the core action front-loaded and the dependency/failure note appended. No filler or repeated schema content.

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?

Completeness is good for a 3-param query tool: it specifies the return description format (useful since there is no output schema), the runtime dependency, and the failure fallback. Minor gaps include pagination/limits on matches and the exact shape of returned objects, but nothing blocking a call.

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%, so the schema fully documents all, props, and selector. The description's 'plus any requested properties' aligns with the props param but adds no syntax or format details beyond what the schema already provides. Baseline 3 is appropriate.

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 precise verb+resource pair: runs document.querySelector(All) inside the client UI and returns match descriptions. This is unambiguous and clearly distinct from siblings like lol_get (generic get) and lol_eval (arbitrary JS execution).

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 DOM-inspection purpose is self-evident, and it explicitly routes to lol_status as an alternative diagnostic if the remote debugging port fails. It doesn't enumerate when-not-to-use versus siblings like lol_eval, but the querySelector framing makes the intended use clear enough.

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