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

Annotations cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=false) but the description adds behaviour they do not: the daily quota cost (30/day), the fact that nothing is persisted, and the default objective. Missing only auth/permission notes and any hint about failure modes when quota is exhausted.

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 short sentences with zero filler; the primary purpose is front-loaded and the non-persistence and quota caveats follow immediately.

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?

No output schema exists, so the description appropriately explains that the return is a set of options rather than a saved artifact. It is nearly complete for a low-risk generator, with the only real gap being parameter semantics for brandId/contentId.

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%, so the description must carry the parameter burden. It explains the count cap ('up to 3') and the objective default, but says nothing about brandId or contentId semantics (e.g. whether brandId is inferred, whether contentId must belong to the brand), leaving two of four parameters undocumented.

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 (generate) plus resource (caption suggestions) and scope (for a content card), which cleanly separates it from the sibling generators generate_body_options, generate_cta_options, generate_hook_options and generate_title.

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?

It gives a clear usage context by declaring 'Returns options only; nothing is saved or applied', which tells the agent this is a preview step and not a mutation, and notes the quota cost. It does not, however, name alternatives or say explicitly when to prefer this over the other generate_* tools beyond the resource name.

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