Create a category

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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=true). The description adds domain behavior not covered by annotations: income categories behave differently from spending ones, and a parent group must already exist. It does not discuss duplicate-name handling or the response, but the annotation bar is already met.

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 short sentences, front-loaded with the core action, then prerequisites, then the one parameter nuance that actually requires judgment. No filler.

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 4-parameter mutation tool with no output schema and annotations covering the safety profile, the description covers the essential prerequisites and the non-obvious parameter. Missing only edge cases (duplicate names, validation failures) that an agent might want.

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%, so the baseline is 3. The description goes beyond the schema by explaining the semantic distinction for `isIncome` (only for money coming in) and by clarifying that `groupId` must reference an existing group. It does not mention `hidden`, but the schema documents it.

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 (create) and resource (budget category) plus its required parent context (inside an existing category group). This cleanly separates it from the sibling create_category_group, which the description explicitly names.

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?

Names two concrete alternatives with the condition that selects them: obtain the group id from `list_category_groups`, or create the group first with `create_category_group`. It also gives guidance on when to set `isIncome`. No explicit when-not guidance, but the routing is clear.

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