list_deliveries

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

With no annotations provided, the description carries the full burden for behavioral disclosure, but it only restates the tool's purpose. It does not mention pagination defaults, ordering, what fields are returned, or any side effects, leaving significant behavioral traits undisclosed.

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, which is concise and front-loaded, but it is also under-specified. It is not overly verbose, yet the lack of relevant detail detracts from what would otherwise be a highly efficient structure.

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 that there is no output schema and no annotations, the description should explain what the response contains or how pagination behaves. It merely states 'List email delivery history,' leaving the return format and pagination behavior unspecified, making the tool description inadequate for a complete understanding.

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 already provides 100% coverage with descriptions for 'limit' ('Max results') and 'offset' ('Pagination offset'), so the description adds no additional parameter meaning. According to the rubric, this yields a baseline score of 3.

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 'List email delivery history' uses a specific verb ('List') and resource ('email delivery history'), clearly distinguishing it from other list_* siblings such as list_articles or list_sources. It lacks an explicit scope, such as date range or recipient filtering, but the core purpose is unambiguous.

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?

No guidance is provided about when to use this tool versus alternatives like list_account_emails or get_publish_status, nor are any exclusions or context given. The description only states the basic action without situating it within the broader toolset.

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