Compare Transaction Groups

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds behavioral context about the default scope ('all your completed statements') and that scope can narrow accounts/products and date ranges. This is useful but not extensive; it does not mention output format or edge cases like empty filters. Given the annotation coverage, a 3 is appropriate.

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 two sentences long, front-loaded with the core purpose and examples, followed by the scope default and customization. Every sentence earns its place; there is no redundant information.

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?

For a read-only comparison tool with a rich schema covering all parameters, the description adequately explains what it does and the default behavior. The only minor gap is that it does not hint at the output format (e.g., a side-by-side table), but since there is no output schema, the agent can infer the result from the tool's purpose. The complexity of nested filter/scope objects is well-handled by the schema.

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 all parameters are well-documented in the schema itself. The description adds little beyond the schema, only briefly mentioning 'scope' and the two filters. Since the schema already explains each field and its semantics, the description does not need to repeat them. Baseline of 3 is correct.

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's function: side-by-side metric comparison of two transaction groups, with concrete examples (category vs category, month vs month). It distinguishes itself from sibling analysis tools like aggregate, group_by, and time_series by explicitly mentioning the comparison aspect. The verb 'compare' is unambiguous.

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 provides clear context on when to use the tool (comparing two groups) and explains the default scope (all completed statements) with an option to narrow it via 'scope'. However, it does not explicitly mention when not to use it or suggest alternative tools for single-group analysis, which would strengthen guidance further.

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