arrange

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

With no annotations, the description carries the full behavioral burden. It does disclose a key invariant ('Every top-level item and library app must appear exactly once') and the omission semantics ('dock / library omitted = unchanged'), which is meaningful value beyond the schema. However, it does not say whether violating the constraint errors out atomically or partially applies, nor whether this operation is undoable.

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?

The definition is short and front-loaded, leading with the verb and scope before parameter notes and the invariant. The telegraphic final sentence ('dock / library omitted = unchanged') trades a little clarity for brevity, but no sentence is wasted.

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 explained. For a destructive full-layout mutation with no annotations, though, the description should say more about failure behavior, required permissions, and undoability; the ordering/completeness rules it does state are helpful but not sufficient on their own.

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%, so the description must explain all three parameters, and it does so for pages (list of lists of ids, row-by-row ordering) and library (apps kept only in App Library). dock is only covered indirectly via 'dock / library omitted = unchanged', leaving its expected contents and whether dock ids must also appear in pages ambiguous – a real gap.

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 opens with a specific verb and scope: 'Set the whole top-level layout at once', which distinguishes it from incremental siblings like move, place_at, and page_op by emphasizing bulk replacement rather than single-item edits. It never names an alternative explicitly, but the 'whole layout' framing is enough for an agent to separate it from granular operations.

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?

Usage is implied by 'at once' – use this when rewriting the entire layout rather than nudging individual items. There is no explicit when-not guidance (e.g., use move/place_at for a single app) and no mention of prerequisites or what happens if the invariant is violated, so the agent must infer the boundary.

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