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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=false), and the description adds real context beyond them: the approximate timing (~30 hours before, or immediately if the slot is sooner) and the automatic fallback at film_by. It stops short of saying whether generation consumes credits, is reversible, or requires an approved plan/slot.

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 the eligibility precondition before the effect and the timing detail. The first sentence is a long run-on with nested parentheses that takes a re-read, but every clause (style match, timing, fallback) carries 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 one-parameter, non-destructive tool with annotations and no output schema, the description covers eligibility, effect, timing, and the no-call default. Remaining gaps are minor: error behavior for ineligible slots and whether the change can be undone.

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 single slot_id parameter has 0% schema description coverage, but the description compensates by tying it to a slot that appears as to_film in get_calendar, which tells the agent what kind of slot ID is valid. It never literally states that slot_id is that identifier or what happens with an invalid/non-to_film slot.

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 action (HypeFox generates the video with AI in the project's style) on a specific resource (a slot that was marked to_film in get_calendar). The to_film precondition cleanly separates it from make_video, make_video_from_audio, and approve_video without needing to open those schemas.

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?

"Use it when the user says they won't film it" gives an explicit trigger, and "Without it, HypeFox does the same on its own at film_by" states the default behavior and the consequence of not calling it. Both when-to-use and the alternative path are spelled out.

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