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

With readOnlyHint and non-destructive already declared, the description still earns credit by disclosing the payload shape: clip dimensions (1080x1920), selectable metadata (mood, setting, phone, sample hook lines) and a download url. That is meaningful return-value context given no output schema exists. It omits result counts or pagination limits, which keeps it from 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?

The gallery definition is front-loaded and the follow-on action is a short second sentence. The long parenthetical of metadata fields is dense but scannable, and no sentence is filler. Minor cost is the run-on quality of the opening sentence.

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 single optional enum filter, read-only tool, this covers resource identity, filter meaning, and returned fields including the download url. The only gap is the absence of any indication of result volume or ordering, which is minor at this complexity level.

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 100%, so the baseline would be 3, but the description goes beyond the bare enum by describing what each 'fits' value means in practice: 'hook-demo before an app's screens, wall under a wall of text, speaking-hook with its own line'. Only the 'insert' value is left unexplained, so it is not fully complete.

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 identifies the resource precisely as 'the public hook gallery: short 1080x1920 clips of people reacting', which separates it from the user-owned media siblings (list_media, list_image_packs, list_video_templates) by calling out that it is a public gallery. It falls short of a 5 because it never states the listing verb or scope (how many clips, ordering) explicitly, though a reader still knows exactly what this returns.

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 downstream usage ('Use them in your own edit, or import_media one into a post'), which tells the agent what to do after calling. It does not say when to prefer this over list_media or list_video_templates, nor any exclusion, so the choice between clip sources is left to inference.

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