Price a call

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

With no annotations, the description carries the full load and does well: it guarantees 'nothing is generated or billed,' explains the answer comes from the API's own dry run, and discloses that results are either exact or an estimate with an upper bound. It stops short of covering errors, argument validation, or auth requirements.

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 tight clauses with the core action front-loaded, then the inputs, then the output guarantee. No sentence is filler; each adds a distinct fact.

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 usefully describes the return content (USD and credits, exact or upper-bounded estimate) and the no-side-effect guarantee. For a two-parameter costing tool fully covered by the schema, nothing an agent needs to invoke it correctly is missing.

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% — both 'tool' and 'arguments' are already documented in the schema, including the enum of curated tools. The description restates the same meaning ('tool's name and the arguments you would pass it') without adding syntax, format, or constraint detail beyond the schema, so the 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 — asking Ideogram what a call would cost — with an unmistakable pre-flight framing ('before making it'). It implicitly separates itself from siblings like ideogram_usage and ideogram_invoices (post-hoc records) and from the generation tools it prices.

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 trigger is clear: use this before making a call, supplying the curated tool's name plus the arguments you would pass it. It does not name alternatives (e.g., ideogram_usage for historical spend) explicitly, so it falls just short of full routing guidance.

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