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 that recipient data is excluded (a privacy/behavioral trait) and explains the purpose of the SES MessageId. However, it does not mention error behavior, permissions, or idempotency, leaving some gaps for a read operation with no annotations.

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 two concise sentences with no waste. The first sentence front-loads the core purpose and the exclusion of recipient data; the second clarifies the significance of the SES MessageId. Every word earns its place.

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 2-parameter read tool with no output schema and no annotations, the description is fairly complete: it explains what is returned (delivery and SES MessageId), what is excluded (recipient data), and why the correlation ID matters. Minor gaps like error handling or explicit return structure are not critical given the simplicity.

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 schema description coverage is 100% for both parameters (delivery_id and organization_id), so the schema already documents them. The tool description does not add any additional meaning to the parameters, leaving them at the baseline level for high coverage.

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 states a specific verb ('Read'), a specific resource ('one delivery'), and its key field ('SES MessageId'), while explicitly noting it excludes recipient data. This clearly distinguishes it from related sibling tools like commsharbor_delivery_events or commsharbor_domain_deliveries by focusing on a single delivery fetch with a correlation ID.

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 a use case ('when you need to chase a message there') but does not explicitly state when to use this tool versus alternatives, nor when not to use it. It provides context on the SES MessageId correlation but lacks exclusions or comparisons to sibling delivery tools.

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