List category groups

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds valuable filtering behavior beyond the annotations by stating that hidden, deleted, and system groups are omitted, which materially affects what the agent can rely on in the results.

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 three short, front-loaded sentences with no filler. The final note about categories being created in YNAB is slightly tangential but still earns its place by clarifying that this tool cannot perform creation.

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?

An output schema exists, so return-value details need not be explained, and the sole parameter is fully described by the schema. Combined with annotations covering the safety profile, the description supplies the remaining essential context: the scope and filtering rules of the list.

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 parameter plan_id is documented in the schema, including the 'last-used' special value. The description adds no parameter-level detail, so the schema does the heavy lifting and a baseline 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 states a specific verb and resource (list category groups) and narrows the result set to groups where a new category can be created, with explicit exclusions for hidden, deleted, and system groups. This is clear enough to distinguish it from general listing tools, though it does not explicitly contrast with any sibling tool.

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?

Usage is implied: an agent should call this when it needs valid category-group IDs for creating a new category. The note that new categories are created in YNAB itself hints this tool is read-only for lookup, but no explicit when-to-use or alternative-tool guidance is provided.

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