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

Annotations cover only the safety profile (readOnlyHint=false, openWorldHint=true, destructiveHint=false). The description goes well beyond them: it discloses asynchronous job semantics, an approximate two-minute wait budget, the degraded response shape (queued/running with an id), the required polling follow-up, and who pays the credits. That is exactly the behavioral context the annotations do not carry.

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 with purpose, then job semantics, then the polling fallback and the credit/label note. Every sentence carries new operational information and none is padding, despite the dense em-dash phrasing.

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?

There is no output schema, so the description must explain return values and it does: either the generated text or a generation object with queued/running status plus an id. Combined with the wait window and polling instruction, an agent has everything needed to invoke and follow through 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 the schema already documents all seven parameters, making a 3 the baseline. The description's only parameter-level addition is restating that title_id is an optional report label and that credits belong to the publisher, which largely duplicates the title_id schema text and says nothing about prompt, model, provider, max_tokens, temperature, or system_instructions.

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 (generate text via AI) and immediately scopes it with concrete artifact types (copy, item descriptions, dialogue), which cleanly separates it from the generate_image/audio/video/music/three_d siblings. An agent can pick this tool without opening the 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?

Explicitly describes the invocation contract: the call blocks up to about two minutes, and if not ready it returns a queued/running generation whose id should be polled via get_generation. That names the follow-up sibling and the condition that selects it. It gives no guidance on when to prefer a different generation tool, but the resource is unambiguous.

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