set_loop

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

Beyond annotations (idempotent, non-destructive), description adds that the region is updated even when enabled=false and playback will not repeat. This gives agents full understanding of side effects without contradicting annotations.

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 paragraphs, each sentence earns its place. Front-loaded with purpose, then clarifies parameters and alternative tool. No fluff.

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?

Given output schema exists and annotations, description fully covers what agents need: what it does, parameter semantics, behavioral nuance, and when to use alternative. Complete for effective tool selection.

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 has 100% coverage, so baseline is 3. Description adds meaning beyond schema: 'start is an absolute beat', 'length is a positive beat duration', and clarifies enabled's effect (region updates but no repetition). This adds significant value.

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?

Description clearly states it sets the global Arrangement loop region and its enabled state, with specific verb 'Set' and resource 'global Arrangement loop region'. It distinguishes itself from the sibling tool 'set_clip_loop' by explicitly naming the alternative for Session clip loops.

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?

Explicitly tells when to use this tool (for Arrangement loop) and when not to (use set_clip_loop for Session clips). Also explains behavior when enabled=false, providing clear context for decision-making.

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