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

Beyond the annotations (which already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false), the description adds real behavioral context: it replaces the cut's previous device, 'none' removes the device, and it preserves sound and timing. That replace-in-place semantics explains why idempotency holds. It does not discuss rate limits or failure modes, so not a 5.

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?

It is compact and front-loads the project-scoping constraint plus the core semantics, so little is wasted. But the telegraphic, semicolon-dense jargon and the huge inline style list hurt readability and make the key routing rules easy to miss.

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 9-parameter mutation with no output schema and near-zero schema coverage, the description covers the primary selection parameters and return identity ('returns the project identity'). It still omits meaning for count, colour, duration, and direction, so an agent would have to guess on those knobs.

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 11%, so the description carries the burden, and it does explain at, cuts, origin, and the style vocabulary. But it is silent on count, colour, duration (only an ambiguous 'duration-preserving' phrase against a 0.04–2 param), and direction, leaving four parameters undocumented in both schema and description.

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 concrete verb and resource ('A designed cut device at real cuts' with enumerated styles) and states the scope ('PROJECT-SCOPED'). It is specific about what is being set and what it produces, though it never explicitly contrasts itself with the sibling set_transitions or set_fades, leaving some overlap ambiguous.

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?

It hints at selection policy ('Content-born transitions first; one family per section') and gives a default routing rule ('cuts=scene (default: real shot changes; jump cuts stay bare)'). However, it names no alternative tool and gives no explicit when-not-to-use condition, so an agent must infer the boundary against set_transitions.

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