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

Annotations already declare readOnly/idempotent/non-destructive, and the description reinforces this with concrete negatives: no upload session created, no media generated, no credits refilled, no billing change. It also adds a genuinely useful caveat that a positive balance does not guarantee sufficient funds or provider availability.

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 read-only guarantee is front-loaded in the first sentence, alternatives and caveats follow in priority order. Every sentence adds decision-relevant information with no filler.

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?

With no output schema, the description carries the burden of indicating what comes back, and it does so at a high level: auth state, credit balance, service configuration flags. Exact response shape and units are not specified, which is a minor gap for a status tool.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies no inputs are needed by framing it as a read-only status check.

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 set: check authentication, available generation credits, and whether generation/upload services are configured. This is clearly distinct from siblings like get_run_status, get_uploads, and the generation tools.

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?

Explicitly says to call it before the first generation and routes the agent onward: use quote_ugc for make_ugc or quote for a direct generator, then compare cost against balance. Both the when and the alternatives are named.

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