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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description correctly spends its budget on semantics instead: units for zoom (scale ratios) versus pan/direction (fractions of image width), the heuristic nature of easing classification, and the caveat that clipping does not remeasure amplitude. That last note is genuinely useful behavioral context an agent could otherwise misread as a data-quality bug.

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?

Four short, dense sentences with no filler, and the core action is front-loaded. Efficient, though the ordering puts measurement units ahead of any indication of what a caller must provide.

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 seven-parameter tool with three competing scope identifiers (slug, video_slug, scene_id) and zero required parameters, the description never explains how to scope a call or what happens if you scope by none, by several, or by an unknown slug. An output schema exists, so return values needn't be explained, but the invocation surface is left largely undocumented.

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 only 29% and the description adds nothing about the parameters — not which of slug/video_slug/scene_id scopes what, not the meaning of limit/cursor pagination, and not the relationship between the inclusive start_ms and exclusive end_ms (the schema covers those two but nothing ties them to a video). With seven params and a third documented, the description needed to compensate and does not.

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 first sentence gives a specific verb and resource: 'Read measured camera movement intervals,' which tells an agent exactly what data comes back. It does not, however, contrast itself with siblings like get_text_track, get_audio_map, or get_frames, so the agent must infer the choice from names alone.

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?

There is no statement of when to call this versus the parallel track tools (get_text_track, get_audio_map, get_frames) or the scene/video lookups. The description only characterizes the payload, never the selection conditions.

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