ynab_set_default_budget

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

Annotations provide idempotentHint, destructiveHint, readOnlyHint. The description adds value by specifying validation against the YNAB API, the return fields (success, default_budget_id, cache_warm_started), and the error case. This complements the annotations without contradiction.

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 concise, uses clear sections (Args, Returns, Examples, Errors), front-loads the main purpose, and every sentence adds value without redundancy.

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 simple with one parameter and clear returns. The description covers input, output, error handling, and usage example. It could mention persistence scope (e.g., session or permanent) but overall is adequate given the tool's simplicity and presence of an output schema (though not shown).

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 input schema only defines budget_id as a string with minLength. The description adds critical semantic info: it is a UUID (format), required, and validated against the YNAB API. It also includes an example referencing ynab_list_budgets for obtaining the UUID.

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: 'Set a default budget so other tools don't require budget_id every call.' It uses a specific verb (set) and resource (default budget) and implicitly distinguishes from siblings like ynab_get_default_budget and ynab_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 explains the benefit of using this tool (reducing need to pass budget_id in other calls) but does not explicitly state when not to use it or mention alternatives. The context suggests setting a default is optional, but no exclusion criteria are given.

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