Get Email Statistics by Category

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

Annotations already mark the operation as read-only, idempotent, and non-destructive, and the description adds the meaningful behavioral constraint that data is available only for the previous 13 months. It does not describe return shape or error behavior, but with annotations covering the safety profile, this is sufficient context.

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 one concise sentence with no redundant wording. The core action and resource are front-loaded, and the 13-month limitation is included as a brief, important caveat in parentheses.

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 simple read-only stats tool with four well-documented parameters and safety annotations, the description captures the essential constraint an agent needs to know: the 13-month limit. No output schema exists, so return structure is not described, but the core invocation context is adequately covered.

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 input schema has 100% description coverage, so every parameter is already explained. The description adds only the high-level notion of 'specific categories' and the 13-month data availability, which is useful context but does not add parameter-level detail beyond what the schema already provides.

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 identifies a specific action ('Retrieve') and a specific resource ('email statistics for specific categories'), which distinguishes it from sibling tools like get_global_stats or get_stats_by_country. The title reinforces the same resource, so there is no ambiguity about what this tool operates on.

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 implies this tool is for category-level email statistics and notes the 13-month availability window, but it does not explicitly state when to choose this instead of get_global_stats or get_stats_by_browser. There are no named alternatives or exclusions, so guidance is only inferable from the resource name and sibling list.

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