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

Annotations already declare this as a safe, read-only, idempotent operation. The description adds useful behavioral context beyond that by disclosing pagination and the most-recent-first ordering, though it does not discuss rate limits or return shape.

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?

A single sentence that is front-loaded and free of waste. It conveys the core action and ordering without unnecessary repetition.

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 simple read-only list tool, the description is minimally adequate: annotations cover safety and the ordering is disclosed. However, with no output schema and weak parameter description coverage, the lack of details about pagination parameters and returned contacts leaves clear gaps.

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%, with just the required id described as 'List id'. The description implies paging via 'Page through' but does not explain limit or cursor semantics, leaving the low-coverage parameters insufficiently compensated.

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?

The description states a specific action on a specific resource: paging through a list's contacts. It also specifies ordering, which distinguishes it somewhat from a generic contacts listing, but it does not explicitly contrast with the sibling list_contacts tool.

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?

Usage is only implied by the phrase 'a list's contacts'. There is no explicit guidance about when to use this instead of list_contacts, get_list, or other list-related siblings, and no prerequisites or exclusions are given.

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