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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the data is precomputed sample data, not the caller's footage, which an agent must know to interpret results correctly. It does not describe payload size or pagination, but none is expected.

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 compact clauses, front-loaded with what is returned and immediately qualified by the sample-data caveat. Every phrase earns its place with no redundancy.

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?

An output schema exists so return-shape details need not be repeated, and the description supplies the one non-obvious fact an agent needs (this is static demo data mirroring the keyed report). Nothing required for correct invocation is missing.

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?

The tool takes zero parameters, so the baseline is 4. The description correctly implies no input is required and gives no misleading parameter guidance.

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 (Return) and resource (precomputed RetentionRail screening report) with concrete detail about what the payload is (a 1:00 YouTube Short). It differentiates itself from the keyed get_screening_report by explaining the report is sample data, though it does not reference its listed sibling get_started.

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?

Implies the usage context clearly: this is demo/sample data rather than the caller's footage, so it is the tool to reach for when a real keyed report isn't appropriate. It stops short of an explicit when-to-use/when-not statement or naming an alternative by name in a routing sense.

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