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

Annotations already cover readOnly, idempotent, non-destructive, closed-world. The description adds genuine behavioral context beyond them: the grid is 'synthetic' (not derived from audio), constant-tempo, and snapping 'preserves exact start/end'. It doesn't explain what the snapping does when a cut is far from a beat.

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?

Two dense sentences with the core operation front-loaded and the caveat second. No filler, though the phrasing is compressed enough that 'preserving exact start/end' takes a second read.

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 tool whose schema includes a deeply nested structure/scene model and 7 parameters, the description explains almost none of it; the structure object's purpose is never mentioned. An output schema exists so return values needn't be described, but the input side is substantially incomplete.

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 0% across 7 parameters, including a large nested `structure` object with scenes, roles, palettes and transitions. The description only explains phase and bpm; beats_per_bar, cut_every_beats, cuts_ms and the entire structure object are left undocumented, so it fails to compensate for the coverage gap.

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 and resource: 'Calculate a synthetic constant-tempo beat/downbeat grid and snap proposed cut times'. The second sentence adds a distinguishing constraint (supply phase explicitly). No direct sibling competes, but it doesn't contrast with get_audio_map, which handles real audio timing.

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?

'Supply phase explicitly; BPM alone cannot recover an audio file's real timing' implies the alternative (real audio analysis) without naming it. There is no explicit when-to-use/when-not statement or pointer to a sibling tool.

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