aua_scroll_until

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

Beyond the annotations, the description discloses concrete termination semantics: bounded by max_swipes and timeout_seconds, halting after two unchanged regional snapshots or an app/display change. It also warns that no_progress does not prove list end, a non-obvious caveat. The swiping behavior is consistent with readOnlyHint=false and openWorldHint=true, but the return status/failure shape is never described and no output schema exists.

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?

Short telegraphic sentences, front-loaded with the primary action and termination rules, with zero filler. The 'no_progress' sentence is slightly opaque since no output schema documents that field, so the reference is under-anchored rather than wasteful.

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?

For a 9-parameter, state-mutating, open-world tool with no output schema, the description covers stopping conditions and one key modifier (region) but leaves the observation modes, direction semantics, and result payload unexplained. It is adequate to call correctly in the common case but incomplete for the full parameter surface.

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 9 parameters, so the description carries the full burden and only partially meets it: it explains max_swipes and timeout_seconds as bounds, and region as the nested-list scoping mechanism. It says nothing about observe, direction (defaulting to 'up', which is surprising for scroll-to-find), duration, settle_seconds, or variation.

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 states a specific verb and resource ('Find a visible selector') plus the mechanism ('swiping only if absent'), which distinguishes it functionally from a bare find or raw swipe. It never names a sibling tool, so an agent must infer which of aua_find/aua_swipe/aua_scroll_until to pick from behavior alone.

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 gives a conditional scoping hint ('Use region for nested lists') and a post-condition constraint ('Does not click the result'), which implies the tool is for locating, not activating. However, it never states when to prefer this over aua_find or a manual aua_swipe sequence, and gives no exclusion for cases where the target is already known to be on screen.

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