Get List Members

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is given. The description still adds real operational context beyond them: an API key is required, each call is one request costing roughly 1 unit, and results carry a cost estimate. It does not disclose rate limits, error conditions, or what happens with private/suspended Lists, so this is good-but-not-rich for an annotated tool.

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 front-loaded paragraph: purpose first, then sibling routing, then auth/cost behavior, then pagination mechanics. Every sentence carries distinct information with no redundant restatement of the name or title.

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 described, yet the description supplies the key return detail an agent needs to continue paging (completeness.nextCursor). With auth, cost model, scope and pagination all covered, nothing material is missing for a read-only paginated list tool.

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 100%, so the schema already documents cursor, listId and responseFormat including the enum meaning, establishing a baseline of 3. The description adds the pagination loop ('call again with cursor set to this result's completeness.nextCursor'), which is useful workflow context, but it does not explain listId link-vs-numeric handling or compact-vs-full tradeoffs beyond the schema.

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 ('Fetch one page of the accounts that are members of a List'), including the lookup key (List ID or List link). It immediately distinguishes itself from tweetapi_list_followers and tweetapi_list_details, so an agent can choose correctly without opening a schema.

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?

Names two concrete alternatives with the condition each covers ('accounts that follow the List' vs 'its counts'), which is exactly the when-to-use-which routing an agent needs in a 50-sibling namespace. No exclusions are stated, but the sibling routing is explicit and unambiguous.

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