fl_select_mixer_track

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

Annotations already declare a non-read-only, destructive, non-idempotent mutation, so the bar is lower. The description adds one useful behavioral detail: the operation verifies the active-track getter after selecting. It does not disclose side effects on the previously active track or failure behavior on guard mismatch, though some of that is encoded in the schema.

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 a single short sentence and front-loads the core action. The trailing 'verify the active-track getter' phrase is slightly awkward but not verbose.

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?

The tool is a guarded write with 4 parameters, but the schema and annotations carry most of that context and an output schema exists. What is missing is any use-case framing or relationship to sibling mixer tools, so an agent gets no help deciding when this tool is the right one.

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 100%, so the baseline is 3 even without parameter details in the description. The description adds no parameter-level meaning; it merely names the action. The schema already explains track_index, allow_master, expected_before, and session_fingerprint adequately.

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 action ('make one mixer track active') on a specific resource ('mixer track'), which separates it from mixer property setters and read-only inspectors. The appended 'verify the active-track getter' clause slightly muddies whether the tool is a selector or a verifier, but the primary verb/resource is unambiguous.

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?

The description offers no guidance on when to use this tool versus fl_list_mixer_tracks, fl_inspect_mixer_track, or the many fl_set_mixer_* siblings. It neither states prerequisites nor excludes cases such as master selection or concurrency-guarded writes. The schema hints at these, but the description itself provides no usage context.

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