create_newsletter

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

With no annotations, the description fully covers behavioral traits: it returns the created newsletter's summary, explains the opt_in_existing behavior, and notes that setting a custom sender_email requires an additional update step due to email verification. No contradictions.

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 concise, with each sentence adding unique value. It is well-structured and front-loaded with the primary action.

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 6-parameter tool with an output schema, the description covers the key complexities (required vs optional, special parameter values, return type). Minor gaps exist for some optional parameters, but overall it is complete enough for most use cases.

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 coverage is 0%, so the description adds crucial semantics for 'sender_reply_to' (two possible values), 'opt_in_existing' (subscription behavior), and the 'sender_email' workflow. However, it does not explain 'description', 'sender_name', or 'subscribe_on_signup', leaving some parameters under-specified.

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 begins with a specific verb+resource ('Create a newsletter'), clearly distinguishing it from update_newsletter and other create tools. The purpose is immediately clear.

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?

Explicitly states that only 'name' is required, explains the values for 'sender_reply_to', and provides guidance on when to use 'update_newsletter' for custom 'sender_email'. No sibling tool ambiguity.

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