Get YNAB spending summary by category

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

Annotations already indicate readOnly and safe behavior. The description adds critical transparency by explaining that the summary is computed client-side from transactions because YNAB lacks a single endpoint. It also discloses rate limit implications and performance considerations, exceeding annotation coverage.

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?

Three sentences with no redundant information. The first sentence states the core function, second provides default behavior, third offers optimization advice. Front-loaded and efficient.

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 no output schema, the description covers key aspects: purpose, date range handling, client-side computation, and performance/rate limit considerations. It would benefit from briefly describing the output format, but is largely complete for a read-only summarization tool.

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%, fully describing parameters. The description adds value by stating the default for since_date and offering usage guidance for date range parameters, helping the agent choose appropriate values.

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 function: summarizing spending and income per category over a date range. The verb 'summarize' and resource 'spending per category' are specific and distinct from sibling tools like ynab_list_transactions and ynab_list_categories. The mention of client-side computation adds to clarity.

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 practical guidance: defaults to last 30 days, suggests narrowing date range for large budgets to keep response small and avoid rate limits. It does not explicitly list alternatives but the context makes it clear when to use this vs. other tools.

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