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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds only usage scope, not pagination, ordering, completion filtering, or other behavioral detail; it does not contradict the 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?

It is a single front-loaded sentence with no wasted language. For a simple list tool, this is appropriately sized.

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?

With full schema coverage, rich annotations, and an output schema, the description does enough to indicate the core usage. However, it omits sibling differentiation (e.g., reminders.list, tasks.get) and does not mention pagination or completion filtering, leaving meaningful gaps for an agent selecting among many task-related tools.

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 both parameters are already documented. The description reinforces the contact-specific scope via "one specific contact" but does not explain limit behavior or add syntax beyond 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 maps a clear user intent ("what they need to do") to task listing and scopes it as overall or contact-specific. It never explicitly says "list tasks" and does not distinguish itself from siblings like tasks.get, but the purpose is readily inferable.

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 gives an explicit trigger condition: when the user asks what they need to do, either broadly or for one contact. It lacks when-not guidance and does not name alternatives such as reminders.list or tasks.get.

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