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

Annotations already declare this is a non-read, non-destructive, closed-world mutation, so the safety profile is covered. The description adds the meaningful null-means-remove behavior, but says nothing about whether existing transitions are overwritten, what duration units/default apply, or what happens if a cut cannot take the transition.

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 short sentences, front-loaded with the main action and immediately followed by the removal case. No filler.

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 bulk mutation over 4 parameters with no output schema, the description covers the primary action and the removal path but leaves duration semantics and overwrite behavior unexplained. An agent could call it, but might guess wrong on timing values.

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 only 25% (only projectId is documented), so the description must compensate and it partly does: it explains that type null strips all transitions and that omitting trackId targets all video tracks. It adds nothing for duration (units, default, or whether it is required with a non-null type), leaving a real 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?

"Put the same transition on every cut of a video track (or all video tracks)" names a specific verb, resource, and bulk scope. It implicitly separates itself from the singular sibling set_transition by emphasizing every cut / all video tracks.

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?

The bulk scope plus the null-to-remove case gives clear context for when to reach for this tool rather than a per-cut edit. It never names set_transition explicitly as the single-cut alternative, so routing still requires a small inference.

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