category-trends

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

No annotations exist, so the description must carry the full behavioral burden. It discloses the return format (JSON) and currency unit (integer cents), which is helpful, but says nothing about required auth, scope limitations, whether it's a read-only aggregation, or how trend direction is computed (e.g., percentage vs absolute).

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 tight sentences, front-loaded with the core analysis then the return-format note. Zero 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?

With no annotations and no output schema, the description carries full burden but only covers purpose and return format. It omits auth/scope constraints, pagination-like limits, and how trend direction is derived, leaving the agent under-informed about behavior.

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 the schema already fully documents all four parameters; the description adds no parameter-level meaning beyond what the schema provides. Baseline 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 analysis: month-over-month category spending change with trend direction. Distinct from sibling spending-by-category (single period) and monthly-summary. Does not explicitly name or contrast siblings, keeping it at 4.

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?

Implies usage via the MoM trend framing, which hints when it's useful versus a flat category report, but provides no explicit when-to-use or when-not guidance, nor names alternatives like spending-by-category.

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