List Payees

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the agent knows this is a safe read-only operation. The description adds no extra behavioral context such as pagination, rate limits, or return format. It only restates the scope, so it adds minimal value beyond 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?

The description is a single, clear sentence: 'List payees for a YNAB plan.' It is front-loaded with the verb and resource, contains no fluff or repetition, and is appropriately sized for the tool's simplicity.

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?

The tool is a simple list operation with two optional parameters, high schema coverage, and strong read-only annotations. The description sufficiently states the purpose, and the schema covers parameter defaults and refresh behavior. No output schema exists, so return-value details are not needed. The description is complete enough for an agent to select and invoke the tool successfully.

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 description coverage is 100% for both parameters (plan_id and refresh), each with clear descriptions. The description 'List payees for a YNAB plan' does not add any additional parameter semantics, but the schema already covers the default and refresh behavior, so a baseline of 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?

The description clearly states the verb 'List' and the resource 'payees', scoped to 'a YNAB plan'. This is specific enough to distinguish from sibling list tools like ynab_list_accounts or ynab_list_categories, even though it doesn't name them. The title adds no additional confusion.

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. It does not mention any prerequisites, filtering preferences, or references to sibling tools. An agent would have to infer usage purely from the resource name, which gives no comparative context.

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