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

With no annotations, the description carries the full burden and does disclose meaningful behavior: timestamp-cited output format [n @ mm:ss], refusal with no charge when a transcript cannot be fetched, and pricing ($0.03 USDC via x402). It omits any latency, rate-limit, or auth detail beyond pricing.

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 refusal rule is stated twice in nearly identical, partly garbled form ('If no transcript can be fetched, the job is refused and you are not charged. Refuses, with no charge, when fetched transcript cannot be fetched.'), which bloats the definition without adding information.

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-parameter tool with no output schema and no annotations, the description covers input modes, output shape, failure semantics, and cost. The only real gap is the mismatch between the mentioned `urls` input and the actual schema.

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% for the single 'task' parameter, so baseline is 3. The description adds the notion of passing video URLs, but references a `urls` parameter that does not exist in the schema, which creates mild ambiguity about how URLs are actually supplied.

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 and resource ('Researches YouTube videos from their real transcripts') and describes the two input modes clearly. The emphasis on real transcripts distinguishes it from sibling research tools like research.topic-deep-researcher and research.topic-news-scanner.

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?

Gives clear context for both invocation paths (pass video URLs, or describe a topic and it finds relevant videos) and states the refusal condition. It does not, however, name any sibling alternative or when to prefer a different research tool.

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