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

Annotations already cover safety (readOnly, idempotent, non-destructive), but the description adds substantial behavior beyond them: render cadence (every 6 hours), encoding specs (H.264, 7 fps, 720p, ≤3 MB), storm-reel trigger (>8 in new snow), retention (1 year), the operator-archiving restriction, and the critical note that media is never returned inline.

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?

Purpose and the 24-hour clip are front-loaded, and most clauses earn their place (cadence, storm criteria, retention, archiving restriction). The single dense paragraph packs a lot of encoding minutiae (7 fps, 720p, 3 MB) that is useful but borderline for a selection-time description.

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 an output schema present, return-value shape needn't be explained, and the description still covers what a caller needs: links vs. inline media, poster JPEG, frame bounds, and the archiving caveat. Complete for a read-only lookup 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 both slug and camId are already documented, including the 'default is every cam' behavior. The description's '(or one cam)' phrasing mirrors the schema without adding new semantics, so baseline 3 is appropriate.

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 ('Rendered timelapse clips for a resort's webcams') and immediately distinguishes itself from the sibling get_cam_timeline ('returns the individual frames'). An agent can tell the two apart without opening either schema.

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 explicit trigger phrases ('show me the last 24 hours' or 'show me the last storm') and names the alternative tool (get_cam_timeline) for the frame-level case. Nothing about when to select this vs. a sibling 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.