fl_set_time_signature_numerator

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, so the write nature is known. The description adds that the tool 'proves' the set operation via FL's PPB/PPQ getter pair, and the schema explains the session_fingerprint is a concurrency guard that refuses after bridge reload or project load. This adds behavioral context beyond annotations, though it doesn't detail side effects or reversibility.

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, dense sentence that conveys the core action and verification mechanism without waste. It is front-loaded with the verb 'Set' and the resource, and the PPB/PPQ reference is meaningful to FL context. No filler or redundancy.

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?

Given the output schema exists and the schema covers all parameters, the description is mostly complete. It explains the core behavior (set and prove) and the schema covers the concurrency guard semantics. A minor gap is that it doesn't explicitly state the numerator range (1-32) or that it's a write operation, but those are in the schema/annotations. Overall adequate for an agent to call it correctly.

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 schema already documents all parameters. The description adds the key semantic that the numerator is 'beats per bar' and that FL exposes no denominator getter, which clarifies why only the numerator is set. The expected_before and session_fingerprint parameters are well-described in the schema, so the description doesn't need to repeat them.

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 'Set and prove beats per bar from FL's PPB/PPQ getter pair' clearly identifies the action (set and prove), the resource (beats per bar / time signature numerator), and the mechanism (FL's PPB/PPQ getter pair). It distinguishes this from sibling tools like fl_set_tempo or fl_set_loop_mode, though it doesn't explicitly name a sibling alternative.

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 implies usage context: it sets the numerator and verifies it via FL's PPB/PPQ getter pair. The schema adds that expected_before is an optional concurrency guard and session_fingerprint is a bridge/project-session guard. However, the description itself doesn't explicitly state when to use this vs alternatives or when not to use it.

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