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

Beyond the destructiveHint annotation, the description discloses irreversibility ('cannot be undone'), a side effect (last_contacted_at is recomputed), scope restriction to the caller's own contact book, and the exact two-phase confirmation protocol with status='confirmation_required', action_id, and plan_token. This is exactly the behavioral context annotations cannot carry.

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?

Front-loaded with the action, then constraints, then the confirmation protocol as a labeled block. Every sentence carries information, though the all-caps emphasis ('OWN', 'PROPOSED') is slightly noisy.

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?

For a single-parameter destructive tool with no output schema, the description covers scope, side effects, irreversibility, and the full confirmation round-trip. Only edge cases (invalid interaction_id, cross-book attempts) are left unaddressed.

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 0%, so the description must compensate; it names the parameter ('Pass interaction_id') and its provenance (from get_person's interactions), which is useful. However, it omits the accepted types (integer or string) and any format or error behavior, leaving the free-form schema value undocumented.

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 and resource: delete one entry of a person's timeline, sourced from get_person's interactions, scoped to the caller's OWN contact book. This distinguishes it from the many other delete_* siblings by resource and scope.

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?

Gives clear context (removing a timeline entry obtained via get_person) and an explicit operational rule: it is proposed, never performed directly, and the write happens only after confirm_action. It does not explicitly exclude adjacent tools such as delete_contact_personal, so it stops short of full when/when-not guidance.

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