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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description meaningfully adds that this call is project-scoped, returns no downloads, never inserts into the video, returns a provider-diverse grid, relays license obligations, and defaults orientation to the project's output frame. These behaviors are not inferable from annotations or 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?

The description is front-loaded with the most important scoping constraint and every sentence adds operational value. It is somewhat dense and uses heavy capitalization/parentheticals, but it is not padded or repetitive.

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 tool without an output schema, it gives a useful high-level return contract (visually reviewable, provider-diverse grid), safety guarantees, and a natural follow-up action. The main gap is the undocumented count parameter and a somewhat vague exact return shape.

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 20%, so the description must compensate. It explains the query semantics, the kind enum and default, orientation defaulting, and project_id scoping. However, the count parameter is left unexplained, so its role or limit remains ambiguous.

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 action and resource: 'SEARCH for b-roll images/clips the user does not have,' scoped to an explicit project_id. It also distinguishes itself by pointing topical video to find_footage and by describing a provider-diverse result grid, so an agent can tell it apart from related search tools.

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 description is explicit about when to use it: generic visual queries, and photo queries for topical subjects via kind='photo'. It also names the alternative for real topical video ('use find_footage instead') and chains to the next step ('Then call add_stock_media with the best id').

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