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

Adds substantial context beyond the annotations: bins are virtual, moves never touch the file or its mediaRef, and delete_bin reparents children without losing anything. That reconciles the destructiveHint=true annotation with actual semantics, telling the agent a delete is structurally harmless. Mirror-bin rename/move/delete restrictions are a behavioral rule found nowhere in structured data.

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 with the conceptual model (what a bin is) before the action list, which is the right order. Dense but mostly earning its space; the 'VIRTUAL ... cannot break a clip's link' sentence is emphasized at length relative to its weight, but it addresses the agent's main fear with this tool.

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?

Eight parameters routed through a single action switch with no output schema, and the description compensates by documenting every action's payload, the item key grammar, the root-bin convention, and the mirror-bin exception. Nothing an agent needs to invoke any of the six actions correctly is missing.

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 per-parameter docs already carry the mapping. The description does add real value beyond them — item key formats ('timeline:<id>', 'motion:<id>'), the empty-string Library root, and which params pair with which action — but it largely restates the schema's action-to-param assignments. Slightly above the baseline, not decisively.

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 resource and verb set: the media pool's bin tree, with all six actions enumerated and what each does. An agent knows exactly this is bin/folder management. It stops short of 5 because it never contrasts itself with the sibling organize_media, so the agent must infer which 'organize' tool to reach for.

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 clear operational sequencing — "call it first — you need the ids" — plus the use case (tidying a project instead of leaving eighty files at the root). It also states important when-not conditions (mirror bins cannot be moved or deleted). No explicit pointer to alternatives, hence 4.

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