list_single_send_stats

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

With no annotations provided, the description bears full responsibility for behavioral disclosure. It only states 'Read-only', which indicates no mutation but omits other traits such as rate limits, response size, or permission requirements.

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 very short (4 words) and front-loaded with the read-only annotation. It is concise, though it could include more detail without becoming overly long.

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 has no output schema, so the description should explain what stats are returned (e.g., fields, date defaults). It fails to do so, leaving the agent uncertain about the output. Also, it does not clarify whether parameters are necessary for filtering.

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 for all 3 parameters, so the schema itself provides adequate meaning. The description does not add any extra information beyond what is already in the schema.

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 specifies the verb 'retrieve' and resource 'Single Sends stats', making the purpose clear. However, it does not differentiate from the sibling 'get_single_send_stats', which might cause confusion about which tool returns stats for a specific send vs. all sends.

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 labels the tool as 'Read-only' but provides no guidance on when to use it versus alternatives like 'get_single_send_stats' or 'get_stats'. No explicit context or exclusions are given.

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