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

No annotations are provided, so the description carries the burden, and it does disclose the return shape (balance, plan name, dailyFreeRemaining, purchase URL). For a zero-parameter read it omits little of consequence — no mention of caching or rate limits, but risk is inherently low and the 'Get' framing plus enumerated outputs implies a safe read.

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 sentences, no waste: purpose first, triggers second, return contents third. Each sentence adds information an agent needs and none restates 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?

With no output schema, the description must enumerate what comes back — and it does, including the actionable purchase URL. Combined with the trigger conditions, an agent has everything needed to decide when to call and interpret the result.

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?

The tool takes zero parameters, so the baseline is 4; the description correctly says nothing about parameters and instead spends that space on return values, which is the only semantic content available.

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 — 'Get the user's current AIGE credit balance' — plus the two adjacent data points (subscription plan, daily-free allowance) it returns. No sibling tool does anything similar, so the agent can immediately separate this from the many generation/deck tools.

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 three explicit triggering conditions: failure with INSUFFICIENT_CREDITS, a direct user question about credit count, and proactively before queuing many generations. This is exactly the when-to-use guidance that most definitions omit.

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