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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered, but the description adds almost nothing beyond repeating that it is a UI action. Key behaviors are undisclosed: whether the selection replaces or extends the current selection, whether it scrolls the timeline, whether it is undoable, and what happens if a clip ID is invalid.

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?

One short, front-loaded sentence with zero filler, which is structurally clean. But the brevity comes at the cost of substance rather than being earned concision, so it cannot score highly on this dimension alone.

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 entire job is UI state manipulation, the definition says nothing about the resulting selection state, the interaction with the current selection, or error conditions, and there is no output schema to fall back on. Only the presence of annotations keeps this from being fully inadequate.

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 coverage is 50%: projectId is documented in the schema, while clipIds is an undocumented array of strings. The description does not explain whether clipIds must come from the open project, whether ordering matters, or how many selection behaviors the array implies, so it does not compensate for the coverage gap. It gets the baseline 3 only because the schema still fully defines the required parameter's type.

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 description gives a specific verb and resource ('Select clips') plus the locus of the effect ('in the browser UI'), which already separates it from data-mutating siblings like update_clips or nudge_clips. It does not explicitly contrast itself with any named alternative, which keeps it at 4 rather than 5.

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 guidance on when to use this versus related tools (update_clips, get_ui_state, set_playhead) and no stated preconditions such as a project needing to be open. The agent must infer the whole usage context from the name alone.

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