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

Adds substantial context beyond the annotations: auth requirements (recipient.email and Pro+), rate limits (8 per request, one manual send per 10 minutes), and the return shape. Annotations only cover the safety profile, so this fills the real behavioral 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 tight sentences, front-loaded with the action, then prerequisites, then limits and return. Every sentence earns its place with no 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?

Though there is no output schema, the description notes the return ('the request plus `next`'), and constraints and prerequisites are all stated. An agent has everything needed to invoke it correctly and anticipate failures.

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 100% and requestId is fully documented there, so the description need not re-explain it. The mention of 'recipient.email' adds an implicit dependency but is a prerequisite rather than param syntax, so baseline 3 holds.

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?

States a specific verb (send a reminder email) and resource (the recipient of a pending request) with a clear scope modifier ('now, outside its schedule'). This distinguishes it functionally from request_replayCallback and request_cancel, though it never names a sibling explicitly.

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 phrase 'outside its schedule' tells the agent when this tool applies versus waiting for a scheduled reminder, and the constraints imply a manual override use case. No alternative tool is named, but the triggering condition is clear.

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