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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new context: the response includes each person's name and variables, and the list can be addressed by either numeric id or uuid — a meaningful disclosure given that no parameters are required.

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 front-loaded sentence with the read marker first, the resource next, and the filter clause last. No filler and nothing redundant.

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?

With five parameters, zero required, no output schema, and 0% schema description coverage, the description should do more. It covers the filter and the identifier pair well but leaves pagination undocumented for a list endpoint that presumably returns paged results.

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 load. It does explain `q` (filters by digits of the phone) and clarifies that `voip_list_id` or `voip_list_uuid` are alternative identifiers, but `page` and `per_page` get no explanation at all beyond the schema defaults.

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 resource (the people on a saved VOIP list) and what is returned (name and variables), which is more than the title restates. It does not explicitly name how it differs from list_voip_lists or remove_voip_list_members, but the 'people on a saved list' framing makes the scope clear.

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 '[read]' prefix and the identifier parenthetical imply this is the read path for list membership, with add_/remove_voip_list_members as the obvious siblings, so usage is inferable. However, there is no explicit when-to-use or when-not-to-use statement and no mention of what happens if neither identifier is supplied.

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