Price of a generation

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

readOnlyHint=true already tells the agent this is a non-mutating call, so the safety burden is covered. The description adds genuine context beyond that: the quote is pre-flight and exact, and the balance is only returned 'when connected', hinting at an auth/connection dependency. It says nothing about rate limits, failure modes for unsupported generators, or how the nested params affect the quote.

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?

Two short sentences, the pricing purpose front-loaded and the usage directive second. Every clause carries information; there is no filler or restatement of the title.

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 read-only pricing lookup with no output schema, the description covers the essential 'what' and 'when'. However, with 0% schema coverage and an opaque nested params object, it leaves the caller without enough to actually construct the quote request, which is a meaningful completeness gap 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 0% for two required parameters, and the description compensates for neither. It never explains the generator enum values or, more importantly, the free-form nested 'params' object whose shape is entirely undocumented anywhere. An agent cannot know what to put in params other than by guessing from the generate_* siblings.

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 (quote/pricing) and resource (a generation) plus the pre-execution timing: 'Exact credit price of a generation before running it.' This clearly separates it from the generate_* siblings that actually produce assets, though it does not name any sibling explicitly. It also folds in the balance read, which partially overlaps get_balance.

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 imperative 'Always show this price to the user before generating' gives a clear trigger condition and even a UX obligation, which is more than most definitions offer. It does not state when *not* to call it or point to an alternative when a price is not needed, so it falls short of a full 5.

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