GetPlanSettings

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, and an output schema exists, so the safety and return profile are covered elsewhere. The description adds nothing beyond restating the returned fields — no mention of auth scope, rate limits, or what happens when the plan has no settings.

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 tight sentence with zero filler, front-loaded with the verb and resource. Nothing could be trimmed without losing content.

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 annotations covering the safety profile, an output schema covering return values, and a fully documented parameter, the description only needs to state the tool's scope — which it does. It is complete enough to call correctly, though a one-clause note on when to prefer it over ListPlans would close the remaining gap.

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 the single plan_id parameter is fully documented in the schema, including the 'last-used' default and the ListPlans pointer. Baseline 3 is appropriate since the description contributes no additional parameter meaning.

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 ('Get') and resource ('a plan's currency and date format settings'), which is more informative than a bare name restatement. It does not, however, distinguish itself from sibling getters like Ynab_GetUser or Ynab_ListPlans beyond the resource noun.

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 offers no when-to-use guidance, no indication of when this is preferable to ListPlans or GetUser, and no prerequisites. The only routing hint ('Use ListPlans to find other plan IDs') lives in the schema, not the description.

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