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

The description adds meaningful context beyond annotations: it discloses the side effect 'Effect: external-email,' explains retry safety with an idempotency key, lists required permissions, and reiterates that no automation will start. While annotations indicate destructiveHint and idempotentHint, the description supplies specifics that an agent needs to invoke safely.

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 and front-loaded. The first sentence states the primary purpose, followed by a non-goal, a side-effect note, retry guidance, permissions, and an API reference link. Every sentence earns its place with minimal redundancy.

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 nested schema, output schema, and annotations, the description covers the essential aspects: purpose, side effects, idempotency, permissions, and non-goals. It lacks only a few operational details like what happens when message_ids is omitted, but that is handled in the schema. Overall, it provides sufficient context for a competent agent.

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 the baseline is 3. The description adds some color by mentioning 'up to five' and 'one explicit test address,' which map to message_ids and recipient, but it does not explain subscriber_id or the body structure beyond what the schema already provides. It adds modest value on top of the schema.

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 opens with a specific verb and resource: 'Sends up to five selected saved Automation email steps to one explicit test address.' It clearly distinguishes from sibling tools by identifying Automation as the target resource and adding the non-goal 'does not start the Automation.' This leaves no ambiguity about what the tool does.

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 provides clear context and an explicit when-not: 'This does not start the Automation or run other actions.' It also conveys that this is for testing saved Automation steps. However, it does not explicitly name alternatives like sequences_send_test or broadcasts_send_test, which would strengthen differentiation.

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