dreamlayer_balance

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, covering the safety profile. The description adds the rounding nuance ('separately rounded buckets may sum to 0.1 less') and the no-cost/no-purchase clarification, which provide modest extra context but the bulk of safety disclosure is carried by annotations.

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 with zero waste: purpose+returns, a genuinely useful rounding caveat, and cost/error guidance. Every sentence earns its place and the core purpose is front-loaded.

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 zero-parameter read-only tool with an output schema, the description is complete. It covers when to use it, what it returns, a subtle numerical gotcha, and error-handling guidance—nothing an agent needs to call it correctly is missing.

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 has zero parameters, so the baseline is 4. The description adds value by enumerating the return values, which gives the agent advance knowledge of what to expect beyond the parameter schema.

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?

The description states a specific verb+resource ('check available credits for this API key') and names the exact return fields (promotional, purchased, available, credit_usd). It clearly distinguishes itself from generation/download siblings by framing itself as a pre-flight balance check.

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?

'Use before paid image work' gives explicit when-to-use context. It also states what it does not do ('does not buy credits') and advises resolving authentication/balance errors before generation, giving clear operational context without naming a specific alternative tool.

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