create_locator

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

The description discloses a side effect (moves playhead to time) and explains the internal reason, adding behavioral context beyond the destructiveHint: false annotation.

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 description is concise with a clear front-loaded purpose and a separate paragraph for side effects and alternatives, no unnecessary verbiage.

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 the tool's simplicity, the description covers the main behavior, side effect, and usage context, and output schema exists to handle return values.

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?

While schema coverage is 100%, the description adds important context about the time parameter's side effect and the rename behavior for name, improving understanding beyond the schema alone.

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 clearly states the tool creates or renames an Arrangement locator at a specific beat position, distinguishing it from sibling tools like set_arrangement_time and get_locators.

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 explicitly tells the agent when to use alternatives: 'Use set_arrangement_time when only the playhead should move, and get_locators to inspect existing markers.'

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