Transaction Time Series

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

Annotations already indicate readOnlyHint true and destructiveHint false. The description does not add information about side effects, authentication requirements, rate limits, or other behavioral aspects beyond what annotations provide. It simply describes the computation, which is consistent with being read-only.

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 concise, consisting of two sentences that efficiently convey the core functionality and a key default behavior. It is well-structured and to the point, without unnecessary detail.

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?

The description gives the essential idea but omits details about the output format (e.g., the structure of the time series result) and does not mention the filter parameter, which is part of the input schema. Given the tool's complexity and lack of an output schema, more context would be helpful for a complete understanding.

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?

The schema provides descriptions for all parameters. The description adds value by explaining that scope defaults to all completed statements and that it can narrow by accounts/products or date range, but this is a minor enhancement since the schema already describes scope. Other parameters like filter are not mentioned in the description, so it does not significantly improve parameter understanding.

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 computes a time series by grouping transactions into week or month buckets and applying a metric, and notes it is useful for trends. This is specific and distinguishes it from other aggregation tools by focusing on temporal bucketing.

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 some usage context (e.g., scope defaults to all completed statements, can narrow by accounts/products or date range) but does not explicitly compare with sibling tools like aggregate, group_by, or compare. It mentions usefulness for trends but lacks guidance on when to prefer this over alternatives.

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