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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond that: the two-part precondition (confirmation + version match) and the blast-radius disclosure that related quotes and orders are left untouched and no delivery is affected.

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?

Three tight sentences, front-loaded with the core action before the preconditions and scope caveats. The last two sentences are distinct (quotes/orders vs. delivery) but border on redundant scope statements.

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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. The description covers preconditions and non-effects well; the only real gap is the undocumented 'key' parameter, which remains opaque for a destructive operation.

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% for all three parameters, so the description carries the burden. It conveys the intent of confirmedDelete ('explicit deletion confirmation') and expectedVersion ('a matching current version'), but says nothing about the 'key' identifier or why the version must match. Partial compensation, not full.

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 precise verb and resource ('Deletes one private saved contact') with distinguishing scope ('private saved contact'), which cleanly separates it from siblings like save_contact, delete_draft, and the order/quote tools. An agent can identify the operation without opening the schema.

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?

The description implies preconditions ('after explicit deletion confirmation and a matching current version') and gives a partial exclusion ('Does not cancel or modify a delivery'), but never names an alternative tool or states an explicit when-not rule. Usage is inferable rather than directed.

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