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

Annotations cover the safety profile (not read-only, non-idempotent, open-world), but the description adds two facts the structured data cannot convey: the call consumes account credits and requires prior user consent. It does not state what artifact is produced or whether credits are refunded on failure, so it is not fully transparent.

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 sentences, both earning their place: the first states the action and cost, the second states the consent precondition. Front-loaded and zero filler.

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?

The consent/credit gate is the highest-value missing piece and it is present, but for a 13-parameter generative tool with no output schema the description says nothing about what it returns, generation latency, or how the story relates to get_story_status. Adequate but with clear gaps.

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 only 8% across 13 parameters, so the schema does the near-nonexistent heavy lifting and the description must compensate — it does not. It mentions no parameter at all, not even the required characterName/theme pair or the 4-24 pageCount range, leaving the agent to infer everything from property names.

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?

Specific verb+resource ('Create a personalized story') plus an explicit statement of the side effect ('spend the connected account's credits'). This clearly separates it from sibling mutation tools like create_story_share_link or create_life_project, though it never names a sibling for differentiation.

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 an explicit gating condition: 'Call only after the user explicitly approves the credit spend.' That is a real when-to-call rule rather than implied usage. It stops short of naming alternatives or stating what to do if approval is denied.

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