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

Adds real context beyond the annotations: 'Nothing is charged' and 'a quote alone creates nothing' disclose the cost and side-effect profile, which matters for a tool whose readOnlyHint is false. There is mild tension with readOnlyHint=false (a quote presumably persists some server-side record), but the description's claim is about images and charges, not quote storage, so it is not a contradiction. It stops short of saying how long a quote_id stays valid.

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?

Front-loaded and dense, with the key constraint ('Nothing is charged') placed early. The colon-chained phrasing makes it slightly run-on but nearly every clause carries actionable information; the closing parenthetical is mildly redundant with the earlier 'before anything is created'.

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?

Covers the full quote-then-create workflow, and an output schema exists so return values need not be explained beyond the mention of quote_id and credits. With six fully described parameters and annotations present, an agent has everything needed to call it correctly.

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 every parameter including nested reference_images is already documented. The description adds a usage hint for reference_images ('give the product photo here') but adds no format, default, or constraint detail beyond the schema. Baseline 3 is correct when the schema carries the semantics.

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 ('gets its exact price in Deepnia credits') and immediately scopes it against what it is not ('before anything is created'). An agent can distinguish it from create_image and from quote_video/quote_voiceover without opening any schema.

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?

Gives explicit when-to-use ('when the user wants Deepnia to make an image') and the concrete next step: show the price, then call create_image with the returned quote_id and credits. It also names the condition that selects that alternative ('once they accept'), leaving nothing to inference.

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