Delete a contact

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

Goes well beyond the annotations by disclosing permanence, no API-level undo, the Google Contacts 30-day trash caveat, empty success return, and the non-idempotent failure mode where a retry after a timeout may hit 404. This fully aligns with destructiveHint=true and idempotentHint=false.

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?

Every sentence earns its place: irreversibility, verification step, return behavior, and failure handling. The core action is front-loaded, and the added detail is dense rather than padded.

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 single-parameter tool with no output schema, the description covers return value, preconditions, irreversibility, and recovery from ambiguous failures. Nothing essential for correct invocation 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 coverage is 100%, with resource_name already fully described including pattern, example, and how to obtain it. The description adds verification guidance but no new parameter semantics, so baseline 3 is appropriate.

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: 'Permanently deletes one contact from the account's Google Contacts.' The phrase 'one contact' distinguishes it from the batch sibling while the resource 'contact' distinguishes it from delete_contact_group.

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 procedural guidance: verify resource_name with get_contact before deleting, and check with get_contact after ambiguous failures before retrying. It does not explicitly name alternatives like batch_delete_contacts, but the 'one contact' scoping makes the primary use clear.

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