set_looper

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

Annotations already declare non-read-only, idempotent and non-destructive, so the safety profile is covered. The description adds nothing beyond that: it doesn't say whether the song change takes effect immediately, whether playback is interrupted, or what happens if only one parameter is supplied (required list is empty).

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?

It is short and front-loaded with the resource and ranges, but it is an incomplete sentence fragment rather than a structured statement. Nothing is padded, yet nothing is fully communicated either.

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 mutation tool in a crowded sibling set with no output schema and no annotations covering effect, the definition is not sufficient to call correctly — it is silent on whether both parameters are required and on the resulting state change.

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 compensate, but it only restates the parameter names and the ranges already encoded in the schema's minimum/maximum. It provides no meaning for 'song' (e.g., a preset/slot index) or whether either parameter is optional.

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 is a noun fragment ('Looper song (1-10) and volume (0-100)') with no verb; the intent to set/change the looper's song selection and volume must be inferred from the tool name. It roughly distinguishes itself from looper_control and list_loops but no explicit statement of what the tool does appears.

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?

No guidance on when to use this versus looper_control, list_loops, or export_loop, and no statement of prerequisites or side effects. The agent gets nothing about context of use.

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