Get Summary for Date Range

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

Annotations already declare read-only, idempotent, and non-destructive. The description goes beyond that by enumerating the actual return shape (periodStart, periodEnd, dailySummaries, categoryTotals, detailedCategoryTotals) and the granularity effect on breakdowns, which is useful behavioral information not present in the input schema or annotations.

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?

Purpose is front-loaded; the parameter block is scannable; the return block is compact. The parameter list is slightly redundant with schema, but it is still short and does not bury the main point.

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 correctly fills the return-structure gapholistically. It could be more explicit about how granularity affects the returned 'dailySummaries' (e.g., weekly grouping), but for a simple 3-parameter read-only tool the description is almost fully sufficient.

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%, with descriptions and an enum/default for granularity. The description merely mirrors that information (parameter names and one-line hints) without adding parameter-level context such as date formats, constraints, or maximum range. Baseline 3 is appropriate.

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 states a specific verb ('get'), a specific resource ('spending summary'), and key constraints ('custom date range', 'configurable granularity') in one sentence. It clearly separates this tool from the weekly-summary sibling by emphasizing the custom range.

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 gives contextual context ('custom date range') that implies when this tool is appropriate, but it never mentions alternatives such as get_weekly_summary or get_current_period, and it does not offer explicit selection criteria (e.g., use this for arbitrary periods, use weekly for predefined weeks). Relies on inference.

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