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

With no annotations beyond the title, the description carries the full behavioral burden and does well: it discloses the six-hour/until-spent expiry, that this approval gates four other tools, that it is a record the agent must never create autonomously, and that a new approval replaces an earlier one. It stops short of error behavior or what a successful call returns, which keeps it from a 5.

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?

The purpose and gating constraint are front-loaded, and every sentence carries operational weight (validity window, dependents, prerequisites, prohibitions). The embedded Portuguese example sentence and long parenthetical add length that could be trimmed, though they do encode required phrasing.

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 three-required-parameter gating tool with no output schema, the description covers prerequisites, validity, dependents, and prohibitions, which is what an agent needs to call it correctly. It omits failure modes (e.g., what happens if user_reply does not match or if called twice) but is otherwise complete for this tool's complexity.

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 100%, so the baseline is 3, but the description adds real meaning for credits: it is the total the user approved and it replaces any earlier approval, which is not stated in the schema. plan and user_reply are essentially covered by their own schema descriptions, so the added value is moderate rather than comprehensive.

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?

The description opens with a precise verb+resource: it records that the USER approved spending credits, and immediately states the scope of that approval (valid until the total is spent, up to 6 hours). It names the sibling tools that refuse without it (generate_sounds, generate_voice, generate_music, sounds_for_folder), so an agent can place it in the workflow without reading other 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?

The description gives explicit when-to-call conditions: only after showing the whole plan with total cost and receiving an explicit yes to that cost in the last message. It also states when NOT to call: never on your own and never because the user asked for a game or said 'do everything' before seeing the cost. Prerequisite and alternative behaviors are both covered.

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