Analysis — Group parity

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

Beyond the readOnly/openWorld annotations, the description discloses real operational behavior: the cost model (one YNAB request per month), a hard 36-month limit, and the fixed gap sign convention. Pointing at overview_request_budget for budget checking is genuine guidance an agent can act on.

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?

Front-loaded with the [READ] tag and the core comparison, and every sentence carries weight (framing, sign convention, id source, month format, cost). Slightly dense, but there is 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?

An output schema exists, so return values need no explanation, and the description still supplies the pieces an agent needs: id provenance, month syntax, sign convention, and rate-limit/cost constraints. Complete for a 6-parameter, 36-month-capped analysis tool.

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 0%, so the description must carry the load: it defines the month format ('YYYY-MM', ISO date, or 'current'), sources group ids from categories_list, and pins down which group is subtracted from which. It does not explain plan_id or include_hidden, leaving those to inference, so not quite a 5.

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 (compare) and resource (two category groups month by month), and enumerates the compared metrics (assigned, activity, balance, gap). The 'group A minus group B' convention and the 'split money between two people' framing make it unmistakable against siblings like category_groups_summary_by_month.

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?

Explicitly scopes when to use it — plans that split money between paired groups where the question is even funding/spending — and gives a prerequisite (get group ids from categories_list) plus a pre-flight step (check overview_request_budget for long ranges). Nothing is left to inference about when this tool applies.

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