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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is fully covered. The description adds that it is 'free to use,' which is a useful extra behavioral detail beyond annotations, and the verbose parameter behavior is partially implied. However, no deeper behavioral context is provided beyond the 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?

Two short sentences, front-loaded with the tool's main purpose and then a quick 'free to use' note. Zero wasted words.

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 an output schema, so return values are covered by structured data. For a read-only balance check with one optional boolean parameter, the description plus annotations are nearly complete. Slightly more context about what 'verbose' affects could be added, but it's not essential.

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 coverage is 100%, so the schema fully documents the single 'verbose' parameter. The description adds the notion of monthly allocation but doesn't add meaning about the parameter itself beyond what the schema provides. Baseline 3 is appropriate.

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: checks the user's credit balance, subscription plan, and monthly allocation. This clearly distinguishes it from siblings like check_video_status and the generation 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?

The description doesn't explicitly name alternatives or exclusion conditions, but its scope is clear: it's the credit/plan check tool, distinguishable from the generation and status siblings. Adding an explicit 'when not to use' would be an improvement, so not a 5.

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