YNAB Auth Status

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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description does not need to restate those. It does add useful context about what is being checked (credentials and write-tool enablement), which is more specific than the tool name alone, though it does not describe response details or side effects beyond that.

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?

A single sentence that front-loads the core purpose and states both checks without wasted words. Every word earns its place.

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 status-check tool with an output schema and safety annotations already provided, the description is complete. An agent can understand what the tool does, what it checks, and that it is safe to invoke.

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 there is no parameter semantic burden for the description to carry. The baseline of 4 applies because no parameters exist to document and the schema covers everything relevant.

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 uses a specific verb ('Check') against a clear resource (YNAB MCP server auth state) and names exactly what is verified: credential configuration and write-tool enablement. This clearly differentiates it from the data-query siblings like get_user or list_budgets.

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 implies the tool is useful for determining whether the server is ready and whether write operations are allowed, but it does not explicitly state when to call it or how it relates to the write-capable siblings like ynab_tool_execute. Usage context is present but only by implication.

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