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

Annotations already note this is non-readonly and non-idempotent. The description adds no behavioral information such as delivery side effects, inability to retract, or asynchronous behavior.

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?

One concise, front-loaded sentence with no filler. Every word contributes to the tool's purpose.

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?

Schema and annotations provide a fair amount of context, but without an output schema or alternative routing guidance, the description leaves some operational context unspecified.

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 documents all parameters with descriptions, so the baseline applies. The description does not extend parameter meaning beyond what is in 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?

Describes a specific operation: sending a template-based message to every subscriber of a list. This is clear on verb and resource, though it doesn't explicitly differentiate from similarly named siblings such as send_message_to_list and send_message_template.

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?

Provides clear context: use when routing a notification template to all list subscribers. No exclusions or alternative guidance are given.

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