subcategory_breakdown

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

No annotations are provided, so the description must carry the full burden. It only states the aggregation level and time filter but does not disclose output structure, inclusion of zero-spend subcategories, sorting, or any data caveats, which is a significant 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?

The description is a single, concise sentence that front-loads the main intent. No filler or redundant wording is present, making it highly efficient for its length.

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 no output schema and no annotations, the description fails to convey critical context about return values, edge cases, or how this tool fits with related sibling tools. The minimal description leaves the agent under-informed for reliable selection and invocation.

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 0% and the description merely restates the roles of 'category' and 'month' without adding format constraints, allowed values, or examples. This adds minimal value beyond the property names already in the schema.

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 returns spend by subcategory within a category for a month. It uses a specific verb ('Spend by') and identifies the resource and scope, which distinguishes it from sibling tools like get_category_breakdown.

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 implies usage when a subcategory-level breakdown within a single category and month is needed. However, it provides no explicit guidance on alternatives, exclusions, or when not to use this tool, relying on the name and context.

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