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

With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: 'Open and Click are ADDITIVE: they are recorded alongside delivery state and never overwrite it.' This is valuable nuance beyond the schema. It does not contradict any annotations (none exist). It does not mention read-only status or return format, but for a list tool this is a minor gap.

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?

Two sentences with zero waste. The primary purpose is front-loaded, and the additive behavior note is delivered succinctly. No redundant phrasing.

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 list tool with 2 params, no output schema, and no annotations, the description covers the core purpose and an important behavioral detail. It does not elaborate on what 'normalized' means or list event types, but these are not essential for invocation. The lack of explicit sibling distinction is a minor gap.

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% (both parameters have descriptions). The description adds no additional parameter-level meaning; it merely echoes the scoping to one delivery, which is already implicit in the delivery_id parameter. Baseline of 3 is appropriate.

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 a specific verb ('List'), a resource ('normalized SES feedback events'), and a scope ('for one delivery'). It distinguishes from sibling tools like delivery_get by focusing on events rather than delivery details. No tautology.

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 gives clear context that this is for a single delivery, which implies a specific use case. However, it does not explicitly mention when not to use it or name alternative tools, leaving some room for inference. Still, the context is sufficient for most agents.

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