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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds value beyond them by disclosing the returned fields and the newest-first ordering, but says nothing about pagination behavior despite exposing page/per_page.

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, front-loaded with the [read] tag and the resource, then the field list. No filler, though the 'added to any draft campaign in the panel' clause is tangential to calling the tool correctly.

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 no-required-param read with rich annotations and no output schema, the description covers what is returned and its ordering. It falls short on the one thing an agent still needs: how paging works and what per_page=50 implies.

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% — page and per_page appear with only type and defaults, no meaning. The description must compensate but never mentions pagination, page size, or defaults, leaving the agent to infer both parameters from their names alone.

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: saved SMS recipient lists, and enumerates the fields returned (name, description, calling code, member count) plus ordering (newest first). It is clearly a read of lists rather than members or campaigns, though it never names the sibling alternatives such as list_sms_list_members or list_sms_campaigns.

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?

Use is implied by the panel-campaign sentence ('A list can be added to any draft campaign'), which suggests this is the discovery step before adding recipients or attaching to a campaign. There is no explicit when-to-use vs. list_sms_list_members or when-not guidance.

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