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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description restates 'Read-only discovery' (redundant) but does add useful content context — preview video URLs and input requirements — though return shape is already covered by the output schema.

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 front-loaded sentence enumerating the catalogue contents, followed by a short qualifier. Efficient and well-structured, with only the trailing 'Read-only discovery' being mildly redundant against the annotations.

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 a full output schema and annotations covering the safety profile, the description conveys enough about contents and purpose. The only meaningful gap is the unexplained 'aspect' filter.

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 0% and the description never mentions the 'aspect' parameter at all. The enum values (16:9, 9:16) are largely self-explanatory, so the gap is modest, but the description adds no filtering semantics beyond the raw enum.

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?

States a specific verb (List) and resource (Motion Graphics templates, genre looks, motion styles) and enumerates the contents, so the agent knows exactly what this returns. It doesn't explicitly name or contrast with the mutating siblings (studio_motion_create, studio_motion_preview), though 'catalogue' and 'Read-only discovery' imply a distinct read-only role.

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 phrase 'Read-only discovery' hints that this is the browse step, but there is no explicit when-to-use, no when-not, and no named alternative such as 'use studio_motion_create to build from these styles.' Usage is only implied.

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