List accounts

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

Annotations already declare readOnly, idempotent and openWorld, and the description adds genuinely useful context beyond them: every account returns in a single YNAB request, closed accounts are included, and the call mutates nothing. It does not discuss rate limits or error behavior, keeping it short of a 5.

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 core purpose and returned fields are front-loaded, and each following sentence earns its place by adding usage context or behavioral facts. Four sentences is slightly more than strictly necessary but nothing is filler.

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?

With an output schema present, return values need no explanation, and the description still covers scope, the closed-accounts inclusion, single-request behavior, and cross-tool id linkage. 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?

Schema description coverage is 100% and plan_id is fully documented there, so the baseline is 3. The description adds no syntax or format detail for the parameter itself; its note that the returned ids are the account_ids other tools take is about output, not the input.

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 ('List the plan's accounts') and enumerates the returned fields (balances, bank link, last reconciliation), which clearly separates it from siblings like get_category_balances or list_plans.

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?

Gives concrete when-to-use conditions: reconciling YNAB with the bank, detecting broken bank links, and flagging accounts unreconciled for months. It stops short of naming an alternative tool or stating when not to use it, so it is clear but not fully routing.

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