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

With no annotations, the description carries the full burden and does well: it discloses the 3-credit cost, that only the first minute of a YouTube link is heard by Scribe v2, the shape of the returned analysis, and the equivalent REST endpoint. It omits auth expectations for api_key and does not state whether url or script is actually required, both of which matter because all schema params are optional.

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?

One dense but front-loaded sentence that leads with the purpose and credit cost before inputs and outputs. Every clause contributes information (cost, source, transcription scope, score format, endpoint), though the packing makes it slightly harder to scan.

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 6-param, unannotated tool with an output schema, the description covers cost, input modes, processing scope, and result shape adequately, so the agent can call it correctly. The residual gaps are the missing sibling routing guidance and the unstated url/script requirement given that no parameter is marked required.

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 50%, so the description must compensate, and it does for the important params: url is characterized as a YouTube link whose first minute is transcribed, script as pasted opening words, and title/thumbnail_words are tied to the promise check. api_key and idempotency_key are not addressed in prose, though idempotency carries its own schema description.

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+resource ('Hook Review of your own opening') and enumerates the outputs (score out of 10 from named counted parts, per-beat verdict, promise check). 'Your own opening' implicitly scopes it away from find_hooks/write_hook, but the description never names close review siblings (review_short, review_video, review_script), so full sibling differentiation is left to inference.

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?

The two accepted input modes (YouTube link or pasted script) and the credit cost give implicit usage context, but there is no explicit statement of when to choose this over review_video, review_short, or review_script. The agent must infer the boundary from the word 'opening' alone.

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