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

Goes well past annotations by disclosing coin spend, the confirmation threshold and needs_confirmation response shape, that unlimited-plan allowances are excluded, and the task-id/polling model. The annotations only flag non-read-only/destructive; the description supplies the cost and consent semantics an agent needs.

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?

Four tight sentences front-load the action, then cost, then confirmation mechanics, then output handoff. Dense but no filler; the only overlap is restating the confirmation token, which the schema also covers.

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 9-parameter, coin-charging mutation with an output schema, the definition covers the critical unknowns: pricing, consent threshold, retry safety, and task polling. Gaps are minor — it doesn't say where to obtain valid preset keys or how speed tiers affect cost beyond 'slower costs more'.

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 100% and each parameter (mode, preset, prompt, max_total_coins, confirmation_token) already carries a detailed description. The description restates the preset/text duality and the confirmation token round-trip but adds no syntax or format detail beyond the schema — baseline 3 applies.

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 the lighting of an image') and enumerates both input modes (preset or text description), plus the image must be a VerseIn media URL. This cleanly distinguishes it from siblings like relight_video, generate_image, and upscale_image.

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?

Explains the confirmation flow explicitly (ask the user, retry with confirmation_token) and directs follow-up to get_tasks. It does not name alternatives such as relight_video for video assets or estimate_cost for pre-pricing, so the when-not guidance is implied rather than stated.

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