arrangement_set_loop

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), so the bar is lower. The description still earns credit by adding 'Undoable', a genuinely non-derivable behavioral fact, and by clarifying the enabled flag can also turn the loop off rather than only set it.

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?

One short sentence with the action front-loaded and zero filler; 'Undoable' is appended as a compact trailing fact. Nothing to cut and nothing buried.

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?

A simple three-parameter setter with full schema coverage, clear annotations, and no output schema, so little prose is required. It is nearly sufficient, with only minor gaps: what happens to an existing loop when a new range is set, and whether start_beat must be less than end_beat (the schema does not enforce it).

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%, so the schema already documents all three parameters and baseline 3 applies. The description does add unit semantics ('in beats') that the schema's terse 'Loop start.'/'Loop end.' entries omit, but contributes nothing else beyond the schema.

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 specific verb ('Set and enable (or disable)') and a specific resource ('the arrangement loop region'), scoped by unit ('in beats'). An agent can distinguish it from arrangement_get or arrangement_build_song, though it does not name those siblings explicitly.

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 rather than stated: you'd call it to define the transport loop range. There is no explicit when/when-not, no mention of arrangement_get as the read counterpart for inspecting the current loop, and no note on interaction with transport_play or scene/clip loop behavior.

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