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

Annotations already declare destructiveHint=true, readOnlyHint=false and openWorldHint=false, so the safety profile is covered. The description adds a concrete precondition the annotations do not: the call requires confirm: true, a behavioral gate the schema only hints at via default: false. It still omits irreversibility and what gets removed alongside the contact.

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?

Two short sentences, both front-loaded and load-bearing: scope first, then the required flag. No filler.

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 mutation with no output schema and no schema parameter docs, the description covers the confirm gate but leaves gaps: what deletion actually removes, whether it is reversible, and how to obtain a valid contactId. An agent can call it, but without full confidence about side effects.

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 carry the burden. It explains confirm fully ('requires confirm: true') but says nothing about contactId — no ID format, source, or example. It compensates for one of two undocumented parameters.

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 contact') and the qualifier 'one' implicitly separates it from the sibling bulk_delete_contacts. It does not name the alternative explicitly, but an agent can tell single-delete from bulk-delete from the wording alone.

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 word 'one' implies this is the single-record path versus bulk_delete_contacts, and the confirm requirement is stated, but there is no explicit when-to-use/when-not guidance or prerequisites (e.g., permissions, cascading effects on campaigns/lists).

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