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

Annotations only flag destructive/non-idempotent/non-open-world; the description adds the crucial detail that it consumes one video credit (Paper Collage 2), that the old video is moved to the reserve, that the slot's scheduled posts are withdrawn, and that the slot keeps its time. That is exactly the context an agent needs before an irreversible action.

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?

Front-loaded with the core action and example, then behavior, then the sales toggle, then guardrails. It is dense but nearly every clause carries non-obvious information; the run-on construction makes it slightly harder to scan than it could be.

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?

No output schema exists, so the description must cover effects, side effects, and preconditions — which it largely does (credit use, reserve, withdrawn posts, confirmation requirement). What the call returns is not described, leaving a small gap for a destructive, non-idempotent operation.

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 already 86%, and the description still adds meaning: it explains the sales:true/false toggle's effect on slot kind and the DM keyword requirement for sales slots. Only slot_id and why are left to the schema.

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 (change a slot's idea) plus the immediate consequence (remakes its video now), with a concrete example (a sales video at 16:05). It is clearly distinguishable from siblings like update_slot, move_slot, or make_video, which don't swap the idea and regenerate in one step.

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 explicit exclusions: not for slots going out within the hour, already published, or mid-render. Also dictates the interaction protocol (show the user what changes, including the 70-20-10 mix, and act only on explicit yes). No sibling tool is named as an alternative, which keeps it from a 5.

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