VAP Media · Unified MCP Server for AI Agents (Flux · Veo · Suno)

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions the return values (available, reserved, usable balances) but doesn't address critical aspects like whether this is a read-only operation, authentication requirements, rate limits, error conditions, or data freshness. For a financial tool with zero annotation coverage, this is a significant gap.

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?

The description is perfectly concise with two sentences that each earn their place: the first states the action, and the second specifies the return values. There's zero wasted verbiage, and information is front-loaded appropriately.

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?

Given the absence of annotations and output schema, the description is incomplete for a financial balance tool. It mentions return values but doesn't explain their meaning (e.g., what 'reserved' vs 'usable' balances represent), units, or format. For a tool that could involve monetary values, more context is needed.

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, and schema description coverage is 100%, so the baseline is 4. The description appropriately doesn't waste space discussing non-existent parameters, though it could theoretically mention that no inputs are required.

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 clearly states the tool's purpose with a specific verb ('Check') and resource ('VAP account balance'), making it immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'estimate_cost' or 'get_task', which prevents a perfect score.

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 provides no guidance on when to use this tool versus alternatives like 'estimate_cost' or 'get_task'. It doesn't mention prerequisites, timing considerations, or any exclusions, leaving the agent with insufficient context for optimal tool selection.

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