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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds the return fields (bounce type, recipient, timestamp) and filter names, which is helpful, but it does not reveal any other behavioral traits such as pagination, rate limits, or result limits. The added context is moderate but not rich.

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 sentence with no filler, front-loading the verb 'List' and quickly covering the resource, scope, and optional filters. Every element adds value.

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?

Given the low complexity, comprehensive annotations, and presence of an output schema (which covers return values), this description is complete. It covers the purpose, the available filters, and the key return fields, fully enabling an agent to understand and invoke the tool correctly.

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 zero parameters, so the description carries the full burden. It lists six optional filters (type, inactive, emailFilter, tag, fromdate, todate), which adds semantic meaning beyond the schema. However, it does not specify value formats or valid enums for filters, so it is not a 5. Baseline for zero parameters is 4.

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 uses the specific verb 'List' with the resource 'bounced email records' and context 'from the Postmark server'. It clearly distinguishes this from siblings like 'bounce' and 'bounce_activate', which imply different operations.

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 explains what the tool does and lists optional filters, but it does not provide explicit guidance on when to use this tool instead of alternatives such as 'bounce' or 'bounce_activate'. Usage is implied by the action but not contrasted with siblings.

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