Get Delivery Stats

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

Annotations already provide readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is clear. The description adds the per-type bounce breakdown, which is more about output content than behavioral traits. No additional context (e.g., pagination, rate limits, aggregation behavior) is disclosed, but the annotations lower the bar.

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 a single, front-loaded sentence that immediately states the verb and object. Every word adds value, with no fluff or repetition of the title. It is appropriately concise for a simple tool.

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 tool is simple with no parameters and has an output schema, so the description does not need to explain return values in detail. The phrase 'aggregate delivery statistics' plus 'per-type bounce breakdown' gives a clear enough picture. However, it could slightly elaborate on the scope of 'delivery statistics' (e.g., success rates, volume) to fully close the gap, even though the output schema likely covers this.

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 tool has zero parameters, so the baseline is 4. The description does not add parameter details, but none are needed. The schema shows no properties, and the description's mention of 'per-type bounce breakdown' hints at what the output will contain, which is sufficient.

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 with a specific verb ('Get') and resource ('aggregate delivery statistics') and adds a distinguishing detail ('including a per-type bounce breakdown'). This differentiates it from sibling tools like get_sent_counts and get_bounce_counts, which focus on individual metrics.

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 the tool is used to obtain a high-level overview of delivery statistics, but it does not explicitly state when to choose this over other specific stat tools (e.g., get_bounce_counts) or mention any exclusions/alternatives. Usage context is inferred but not clearly articulated.

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