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

The description adds behavioral details about supported features and version differences beyond the annotations, which are minimal (all false hints). However, it does not disclose side effects, authentication requirements, or error behavior, so it partially carries the transparency burden but leaves gaps.

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?

Three brief sentences with no filler. Each sentence provides essential information: core function, supported features, and version usage. Information is front-loaded and efficiently structured.

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?

The description covers core functionality and version selection, but does not mention authentication, response format, or error handling. With 13 parameters and no output schema, more context could be expected, though the schema covers parameter details.

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%, so all parameters are already documented. The description reinforces the connection between version and content types but adds little beyond what the schema states. Baseline 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 the tool sends a transactional email via a specific API, distinguishing it from sibling tools like send_test_email or create_campaign. It also specifies supported content types and versions, making the purpose unmistakable.

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?

It provides clear guidance on when to use API version 1.0 vs 2.0 based on content type, but does not explicitly state when to choose this tool over alternatives or exclude other tools. The context is clear but lacks explicit when-not guidance.

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