delete_contact

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

With no annotations, the description carries the full burden. It usefully discloses the destructive nature and the confirm guard, and the word 'local' implies remote/server contacts are untouched. It does not state irreversibility, error behavior when confirm is false, or permission requirements.

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, zero filler, with the action stated first and the hard precondition immediately after. Nothing to trim.

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 not be explained. The description covers scope ('local') and the safety precondition for a simple two-parameter mutation; only reversibility/remote-contact side effects are left unstated.

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 documents the confirm parameter's required value, which is the non-obvious one; contact_id is self-explanatory and required. Partial but meaningful compensation.

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 a local contact'), which is enough to separate it from delete_message and delete_folder in the sibling list. It does not explicitly name the sibling it competes with (e.g. upsert_contact), so it stops short of full differentiation.

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?

'Requires confirm=true' gives a real precondition for invocation, which is more than implied usage. However, it offers no when-to-use/when-not guidance and names no alternative for editing rather than removing a contact.

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