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

Goes well beyond the destructiveHint/readOnlyHint annotations by disclosing the cascade (timeline, relations, birthday reminder), irreversibility, and the two-phase propose/confirm protocol with the returned status='confirmation_required', action_id and plan_token. It does not state permission requirements or what happens on a stale/expired plan_token, so it stops short of 5.

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-loads the destructive action and its cascade, then the alternative, then the CONFIRMATION protocol — a sensible information order with no filler sentences. The bare 'Pass contact_id' clause is slightly redundant, and the trailing confirmation paragraph is dense but earns its place.

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 destructive one-parameter tool with no output schema, the definition covers blast radius, irreversibility, the safer alternative, and the exact confirmation handshake and return fields an agent must handle. Nothing essential to invoking it correctly is missing.

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% and the schema only types contact_id as integer|string, so the description's 'Pass contact_id' does add the parameter's role but supplies no format, source (e.g., from search_personal), or ambiguity resolution. Adequate for a single required identifier, but no real semantic depth.

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 (delete) plus the exact resource and scope ('a person from the caller's OWN contact book'), and enumerates the cascaded objects removed. It is clearly distinguishable from the sibling update_contact_personal, which it names as the non-destructive alternative.

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?

Explicitly gives the when-not case ('to hide someone instead, update_contact_personal archived=true') and the required follow-up path (confirm_action) instead of leaving the agent to infer either. Both the alternative tool and the confirmation gate are named.

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