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

Discloses that it provides an estimate, not a charge, and that the exact amount is returned upon creation. No annotations exist, so the description carries the full burden; it adequately covers the non-destructive, read-only nature.

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?

Three sentences with no wasted words. The first sentence delivers the core purpose immediately. All sentences add unique value: purpose, clarification, and usage guidance.

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 simple estimation tool with no output schema, the description covers purpose, usage context, behavioral nuance, and a sibling reference. Could mention return shape, but not critical.

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 50% (2 of 4 parameters have descriptions). The description reiterates that model and resolution are required for manual mode, adding no new info beyond the schema. Baseline 3 is appropriate.

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 clearly states the tool estimates credits for a generation before creation using published per-model rates. It distinguishes itself from create tools by emphasizing 'BEFORE creating it' and referencing the exact charge returned later.

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 suggests pairing with check_account to confirm affordability. Implies usage as a pre-check before creation. Does not list specific when-not-to-use scenarios, but context is clear.

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