master_build_chain

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

Adds real behavior beyond the annotations: a hard refusal precondition when a Limiter already exists, the fact that the whole operation is a single undo step (reversibility), and that it creates devices rather than editing them. It doesn't state what the response contains or what happens if the job is stale, but for a non-destructive, non-idempotent mutation the key risks are covered.

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?

Front-loaded with the action, then preconditions and follow-up, with no filler sentences. Slightly dense and grammatically compressed ("the limiter's input gain are set from it"), which costs a little readability but not content.

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?

No output schema exists, yet the description implies the outcome (chain added, one undo step, then re-capture and verify). Return shape and error details are unstated, but the agent has enough to call it correctly and knows how to validate the result.

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 already 100%, so baseline is 3, but the description adds causal meaning the schema doesn't: `target` sets the limiter ceiling, `job` is used to derive the compressor threshold and limiter input gain, and `glue` is optional with a default. That is meaningful semantics beyond the field descriptions.

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 concrete verb and resource: place a mastering chain (glue Compressor + true-peak Limiter) at the end of the master, with specific settings (2:1, slow attack, soft knee, ceiling at target). This is clearly distinguishable from master_check, master_targets, and devices_set_params, which appear as siblings in the same domain.

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?

Gives the workflow context (supply a capture job of the master so thresholds/gain are derived from it), an explicit exclusion path (refuses if a Limiter already exists — adjust that one with devices.set_params), and the follow-up step (capture again, then master.check). When-to-use, when-not-to-use, and the alternative are all present.

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