x_lists_owned

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: output is compact and sanitized, and names/descriptions are third-party text that must be treated as data, not instructions. This is meaningful beyond the structured annotations, though it does not discuss rate limits or authentication nuances.

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 sentences with no fluff. The primary purpose is front-loaded, and the security note about third-party text is a high-value addition that earns its place. It is concise yet informative.

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?

Given an output schema exists, the description need not explain return values. It covers core purpose, default target, output style, and a safety caveat. With read-only and non-destructive annotations, plus fully documented parameters, nothing essential is missing for an agent to invoke this correctly.

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 all parameters are already documented. The description adds minimal parameter-level meaning beyond something like the default to the authenticated user, which the schema also states. It earns the baseline score but does not enrich parameter understanding further.

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 verb and resource: 'returns the lists a user owns,' and clarifies it defaults to the authenticated user. This distinguishes it from sibling tools like x_timeline_user or x_list_members by emphasizing ownership. The phrase 'compact, sanitized page' further scopes the output.

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 description gives clear context: it reads lists owned by a user, defaulting to the authenticated user, and users can be specified via the 'user' parameter. It does not explicitly name alternative tools or exclusion conditions, but the ownership-focused wording makes the intended use fairly obvious in context.

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