fl_transport

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

Adds real context beyond the annotations: nothing is written to any file, FL is not launched, playback restarts from the beginning even when already playing, and the return value is {playing, mode}. Minor tension with idempotentHint=true since a repeated 'play' restarts playback, but the description discloses this rather than hiding it, so it informs the agent.

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 core action and its effect on files, and every sentence carries information. It is dense and semicolon-heavy, bordering on run-on, which slightly slows parsing but does not waste words.

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?

With no output schema, the description supplies the return shape ({playing, mode}), the runtime prerequisite, the mode fallback behavior, and the handoff to fl_render for actual audio. Nothing an agent needs to call this correctly is missing.

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%, yet the description still adds semantics the schema lacks: 'song' means arrangement, 'pattern' loops a single pattern, the pattern number is selected first, omitting mode preserves FL's current mode, and play always starts from the beginning. This is meaningful enrichment over bare enum-like strings.

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 pair (play/stop) and resource (the open project's transport in the running FL), and explicitly scopes it as non-file-changing. It also distinguishes itself from fl_render, which saves and closes FL, so an agent can separate it from the nearest sibling.

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 clear preconditions (FL must already be open with a project; use project_write(open=true) otherwise) and names the alternative for audio capture (fl_render). It does not state when *not* to use it in favor of fl_probe or fl_call, but the routing guidance it does give is strong.

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