params_set

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

Annotations already declare non-readonly, idempotent, non-destructive. The description adds genuinely new behavior: values are validated as a batch before any write ('All are checked before any changes') and the whole call collapses into 'one undo step'. It does not say what an invalid value returns, which keeps it short of a 5.

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?

Three short sentences: what it sets and the key format first, the atomicity guarantee second, the alternative last. No filler, nothing to trim.

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 two-param mutation with full schema coverage and annotations, the description covers addressing, range expectation, atomic validation, and undo granularity — enough to call it correctly. It stops short of describing error/failure reporting, the only real gap for an agent that might pass an out-of-range value.

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 coverage is 100% for the two top-level params, but the schema's 'values' is an opaque number map — the description supplies the key syntax and the per-parameter range expectation ('plugins are usually 0-1'), which the schema does not. That is real added meaning beyond the schema, though the track-id-vs-index distinction is left to 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 and resource ('Set parameters of a track') and immediately pins down the addressing scheme with the params.list key syntax (instrument:<id>, fx:<slot>:<index>). It also names a sibling alternative (devices.set_params) so the agent can tell the two apart without opening either schema.

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 routes builtin-effect edits to devices.set_params 'by name' as the simpler path, implying this tool is for the raw-list key/range case. There is no hard when-not statement (e.g. do not use for device-level params at all), but the routing condition is clear.

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