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

Annotations declare readOnlyHint=false and destructiveHint=true, which is surprising for a 'list' tool; the description earns credit by explaining why, disclosing that it may mark stale private upload records as uncertain. This is real context beyond the annotations, though it never clarifies what 'uncertain' means or whether that mutation is reversible.

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?

Two tight sentences, with the core purpose front-loaded and the side-effect caveat appended. Nothing is filler, though 'opaque upload_ref values' is padding that does not obviously map to any parameter.

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?

With no output schema, the description should carry more: it omits the return shape, whether upload_ref values are the identifiers the agent must feed into other tools, and pagination/limit behavior. It does cover the one non-obvious trait (the destructive side effect), which keeps it at minimum-viable rather than inadequate.

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 33%: only customer_id is described, while limit (1-50, default 20) and connection_context (opaque mctx token) are undocumented. The description gestures at customer scoping ('one owned customer') but adds no meaning for limit or connection_context, so it does not compensate for the coverage gap.

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?

Specific verb (List) plus resource (recent direct video uploads) and a scope qualifier (for one owned customer, using opaque upload_ref values). An agent can tell this apart from upload mutation tools like google_ads_video_upload_prepare/confirm, though the description never names a sibling explicitly.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative is named. The only routing-adjacent sentence ('never retries an upload') describes behavior rather than selection criteria, leaving the agent to infer that this is the inspection counterpart to the upload tools.

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