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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds genuinely new behavior: results include alternative examples, low-sample results are suppressed, and duration_s expands to a ±50% window unless explicit min/max_duration_ms bounds are given. What is missing is how allow_broaden changes the outcome and whether sequences are ranked or randomized.

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 sentences, front-loaded with what the tool yields, then the one non-obvious default. Dense and waste-free, though the telegraphic fragment style makes the first sentence read as a data label rather than an action.

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 explanation is rightly omitted, but for a 5-parameter tool with a 9-field nested filter object and 0% schema description coverage the description leaves too much undocumented. The agent cannot tell what filters do or how allow_broaden affects suppression without guessing.

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% across 5 parameters, including a nested filters object with nine sub-fields (tone, brand, voice, aspect, year ranges, industry, duration bounds). The description explains only duration_s and alludes obliquely to min_videos via 'sample-size suppression'; limit, filters, and allow_broaden receive no semantic explanation anywhere.

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 names the resource precisely (observed narrative role sequences and per-video duration distributions) but is a noun phrase with no verb telling the agent what it does with them — retrieve, aggregate, or compare. It does not differentiate itself from adjacent siblings like pattern_search, trends, get_video_structure, or plan_structure, so the agent must infer the distinction.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites, and no exclusions. The only guidance-like sentence concerns the duration_s window default, which is parameter behavior, not usage routing.

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