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

Despite annotations (readOnlyHint=false), the description adds substantial context beyond them: project-scoping ('PROJECT-SCOPED: this call acts only on the explicit project_id'), the side-effect boundary ('a local edit — the rest of the edit is untouched'), the state change ('Creates a new EDL version'), and the return format ('returns the project identity with its result'). No contradiction with annotations.

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?

Dense and front-loaded — the critical scoping constraint leads, followed by the operation, side-effect boundary, snap behavior, and sibling routing. Every sentence carries information with no filler, though it packs multiple clauses into long sentences that could be split for readability.

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 mutation tool with no output schema, the description covers everything an agent needs: scope, one-operation behavior, side-effect guarantee, EDL versioning, snap semantics, return value, and the source-vs-output routing rule. Nothing required to call it 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 coverage is only 25%, so the description must compensate and does: it clarifies that start/end are SOURCE-seconds of the main video (resolving the timeline ambiguity), and explains snap_to_words ('keeps neighbouring words whole'). project_id is already well-described in the schema, and the description reinforces the explicit-scope requirement. Minor gap: snap_to_words is explained but its default is not stated.

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 says 'Remove ONE source-time range from the current keep set' — a specific verb (remove), resource (source-time range in keep set), and operation scope. It explicitly names cut_output_range as the sibling it is not, telling the agent apart from the edited-output sibling without opening either schema. This is precise and unambiguous.

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 gives explicit when/when-not guidance: 'SOURCE seconds of the main video ONLY — when the user gives times of the EDITED video... use cut_output_range.' It names the specific alternative and the exact condition that selects it, which is the gold standard for usage routing.

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