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

Adds genuinely non-obvious behavior beyond the annotations: HypeFox renders the video roughly 30 hours ahead and consumes one of the user's videos at that point. That is the kind of resource-side-effect disclosure an agent cannot get from readOnlyHint/destructiveHint/idempotentHint. It still does not say what state the slot moves to after approval or what happens if the user has no videos left.

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, purpose front-loaded, followed by the timing/side-effect and the conditional trigger. The parenthetical is slightly awkward but carries real information, so nothing is wasted.

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 mutation with no output schema, the description covers purpose, trigger, prerequisite, and the main side effect (video consumption). The remaining gap is outcome — what the slot looks like after approval and failure modes when no video is available.

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 schema has 0% description coverage and the description never mentions slot_id or where to obtain one. The parameter is a single self-describing identifier, so the cost is low, but no added meaning is supplied beyond the field name.

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 concrete verb and resource ('Approves an idea in the calendar'), so an agent knows this commits a slot's idea rather than a plan or a finished video. It stops short of explicitly contrasting with the adjacent siblings approve_plan, approve_video, or skip_slot, so the boundary is inferable rather than stated.

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 a real usage rule: 'In Automatic only slots that asked for real facts need it, after update_slot' — a condition plus a sequencing prerequisite. It does not cover the manual mode case or name what to do instead when the condition fails (skip_slot, change_slot_idea), so it is clear context without full exclusions.

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