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

Beyond the readOnlyHint annotation, the description adds rich behavioral details: ordering by due time, that follow-ups send nothing by themselves, and the semantics of completionReason distinguishing manual vs platform closure. No contradiction with annotations.

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?

Four sentences with no redundant content. The core purpose is front-loaded, and the subsequent details about ordering, non-sending behavior, scopes, and completionReason each add distinct value.

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 behaviors and scope semantics, and the schema fully documents parameters. However, with no output schema, it doesn't enumerate the return fields beyond completionReason, leaving a small gap for agents expecting a full response shape.

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?

The schema covers all 7 parameters with 100% coverage, so baseline is 3. The description adds substantial context for the scope parameter, explaining each enum value and default behavior based on key type, which goes beyond the schema's short description.

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 states a specific verb and resource ('List follow-up tasks') and defines what a follow-up task is: reminders for a person to get back to a contact. It also includes read-only and ordering details, which distinguish it from create/update siblings.

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 for when to use the tool (listing reminders) and detailed guidance on scope selection based on API key type, including default behavior. It does not explicitly name alternatives, but no competing list tool exists among siblings, so the read-only framing and scope instructions are sufficient.

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