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

With no annotations, the description carries the full behavioral burden, and it does disclose the one-credit cost, which is genuinely useful for a paid generation call. It omits everything else that matters for a write/generate tool: whether the result is persisted to the account (recoverable via get_hook/keep_hook?), what happens on failure and whether a failed call still charges, and authentication expectations for the api_key parameter.

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?

It is a single sentence with the name and cost front-loaded, so nothing is buried. But the phrasing is dense and cryptic ("as beats with seconds counted from their words", "labelled as written") and spends its words describing the output shape that an output schema already covers, rather than on missing parameter guidance.

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 the lengthy output-format description is largely redundant, while the real gaps — semantics of subject and hook_type, and whether the generated hook is saved — go unaddressed. For a 4-parameter billable generation tool with zero annotations, the definition leaves too much for the agent to infer.

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 only 25% — only idempotency_key is documented in the schema. The description gestures at "your subject" but never explains the subject parameter's expected form, and it says nothing at all about hook_type, which is the parameter most likely to change the output. The description 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?

"Hook Creator" plus the elaboration of beats/seconds/shot plan makes it inferable that this generates a new hook script for a subject, and "Same as POST /v1/openings" confirms it is a generation endpoint. However, the description never states plainly that it creates a hook, and it does nothing to distinguish it from siblings like remix_hook, review_hook, write_script or find_hooks — an agent must guess from the name alone.

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 when-to-use statement, no prerequisites, and no mention of alternatives such as remix_hook (for reworking an existing hook) or review_hook (for critiquing one). The only guidance-like signal is the credit cost, which tells the agent this is a billable action but not when to choose it.

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