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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=false, lowering the bar. The description adds the valuable clarification that the contact record survives, but it does not mention that removal accepts phone numbers (possibly non-contact identifiers) or what happens if an entry is not in the list — meaningful gaps for a destructive membership mutation.

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?

One short sentence, front-loaded, with zero filler. Its brevity is appropriate in form even though content coverage is thin.

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, multi-parameter mutation with no output schema and low schema coverage, the description leaves the phone_numbers path, partial-failure behavior, and list-vs-contact semantics unexplored. The essentials are only partially covered.

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 only 33% (only 'id' is described as List id). The description says nothing about contact_ids or phone_numbers, so an agent cannot tell from either source that removal can target raw phone numbers as well as contact IDs.

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+resource (remove contacts from a list) and adds the key qualifier that contacts persist, which distinguishes this from delete_contact. It does not name a sibling explicitly, but the effect is clear enough for an agent to differentiate.

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 parenthetical implies 'use this when you want to unassign rather than delete', but there is no explicit when-to-use/when-not statement or reference to add_to_list or delete_list as alternatives. Usage is inferable rather than stated.

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