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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=false, so the safety profile is known. The description adds the genuinely useful note that collapsing can hide information required for the next step, which explains the destructive hint in practical terms, but says nothing about what happens when the target is already collapsed, and nothing about permissions or side effects on selection/focus.

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 short sentences with the action up front and the caution immediately after; nothing is wasted. Minor deduction because the caution's phrasing ('information needed for the next action') is slightly abstract for an operational instruction.

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 and annotations are rich, so return values and safety need not be re-explained. But for a 17-parameter tool with an enum target and multiple fallback strategies, the description gives no indication of which target types are valid for collapse or how it behaves when the element is not expanded, leaving a real gap.

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 100% across all 17 parameters, each with its own documentation, so the schema carries full param meaning. The description contributes no guidance on which targeting mode (id, label, coordinates, ocr_text, selector) is preferred for collapse, so baseline 3 applies.

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 concrete verb (collapse) and concrete resources (expanded tree item, menu, disclosure control), which is more specific than the sibling name computer_expand alone. It does not distinguish itself from the near-duplicate ui_collapse or from computer_toggle, which could also collapse a control, so an agent still has to guess which of the three to call.

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?

'Inspect the target first' gives a precondition, and 'avoid hiding information needed for the next action' gives a caution about when not to collapse. However, it never names an alternative or says when computer_expand, ui_collapse, or computer_toggle should be chosen instead, leaving the selection decision implicit.

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