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

Annotations only declare readOnlyHint=true; the description adds substantial context beyond that, notably that it uses the preset's music-brief text ('mittel bis schnell, 100–128') rather than the measured beat grid, that lab_apply_rhythm is the only tool that reaches for lab_beatgrid's data, and that it touches no state or credits. This is exactly the kind of caveat an agent needs before trusting the output.

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: the core 'would give, changes nothing' claim is the first clause, followed by use cases and then the important grid caveat. It is dense prose with a mixed-language artifact (`angewendet: false`) that slightly hurts scannability, but no sentence is filler.

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 read-only preview tool with no output schema, the description covers scope, non-mutation, the alternative tool, and the critical measurement-vs-text caveat. The only gap is that the shape of the returned durations is never described, which matters since the return value is the entire point of the tool.

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 both `seq_id` and `anzahl`, including the 400 behavior when the timeline is empty. The description's mention of passing `anzahl` for an empty sequence restates schema content rather than adding syntax or format detail, so the baseline 3 applies.

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+resource+scope: it reports what durations the project's cutting preset WOULD produce for a sequence, and explicitly states it changes nothing. It also distinguishes itself from lab_apply_rhythm, so an agent can route correctly without opening schemas.

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 two concrete use cases — previewing the consequence before lab_apply_rhythm writes it, and sizing a clip-less sequence via `anzahl` — and names the alternative tool plus the condition that selects it. Nothing is left to inference.

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