Create a category group

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false, so the safety profile is covered. The description adds domain behavior the annotations cannot: the group starts empty, must be populated separately, and is restricted to spending groups. It does not mention duplicate-name behavior or what happens on repeat calls, which is a minor gap.

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?

Two sentences, zero filler, and the core action is front-loaded before the workflow and constraint details. Every clause carries information the agent needs.

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?

For a two-parameter mutation with full annotation coverage and no output schema, the description supplies the essential workflow and domain constraint. It stops short of describing the created resource's identifier or duplicate handling, which an agent might want, but nothing critical 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%, so both parameters (name, hidden) are already documented in the schema. The description adds no format, constraint, or default information beyond that, so the baseline of 3 applies.

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 ('Create an empty category group') and immediately defines its scope ('to file categories under'), which cleanly separates it from create_category, list_category_groups and update_category_group. The clarification that groups are spending groups adds precision beyond the name.

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 the when (to file categories under), the follow-up alternative ('then fill it with create_category'), and an explicit when-not: income groups cannot be created via the API and every budget already has one. An agent knows both the workflow and the boundary condition.

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