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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered without description help. The description adds the aggregation semantics (totals by category, date-bounded), but says nothing about pagination, result ordering, or how empty categories are handled.

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?

A single front-loaded sentence that states the metric, the grouping dimension, the time bound, and the group scope with no filler. Every clause earns its place.

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, the description usefully characterizes the return as category-grouped totals, which is the key thing an agent needs. It omits breakdown/parent-child drill behavior and result shape details, but is otherwise adequate for a 7-parameter analytics query.

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 every parameter (types, currencies, dates, groupId, parentId, breakdown) is already documented in the schema. The description only restates date range and group scoping, adding no syntax or semantics beyond 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 names a specific verb and resource — spending/income totals grouped by category over a date range — which is enough to distinguish it from aggregation siblings like get_monthly_summary and get_consolidated_balances. It stops short of explicitly differentiating itself from those siblings by 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?

It conveys scope (all groups vs. one group, date range) but gives no explicit when-to-use guidance or named alternatives among the many list/summary siblings. Usage is only implied from the resource being an aggregation over categories.

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