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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and a closed world, so the safety profile is covered. The description adds behavior the annotations cannot: pagination via offset/limit, that `groups` carries folders/collections, and that list-less catalogues are returned in full. Return-item shape is the only gap.

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?

A single dense paragraph, front-loaded with the `[read]` tag and the core purpose before the mode branching. Every clause carries information about a distinct mode or parameter, though the semicolon-heavy packing slightly hurts scanability.

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 read-only listing tool with no output schema, the description covers the two invocation modes, the parameter meanings, pagination, the `groups` structure, and the whole-catalogue exception. An agent can call this correctly and interpret the response without further documentation.

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?

There is 0% schema description coverage for all 5 parameters, so the description must carry the load, and it largely does: `name` selects the catalogue, `query` is a substring match over id/name/etc., and `category` is an exact collection/folder/category id with concrete examples ('cinematic' luts, sfx categoryId, transitions folderId). Only `limit`/`offset` are mentioned in passing, with no bound or default noted.

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 states a specific verb and resource: it lists the library ids a `video_project` can reference, and it enumerates the catalogue set. That is far more specific than a restatement of the name. It does not, however, differentiate itself from sibling tools such as video_editor_overview or video_editor_example, which is the one thing keeping it from a 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?

The two operating modes are stated explicitly: omit `name` to enumerate all catalogues, supply `name` to search that catalogue's list. The description also notes which catalogues have no list and are returned whole. It gives clear context but no explicit 'when not to use' or named alternative, so it stays at a 4.

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