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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds two useful pieces beyond that: result ordering ('newest first') and an auth prerequisite ('Needs sign-in'), which an agent must know before calling.

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 compact sentence plus a short auth note; scope and ordering are front-loaded and nothing is 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?

For a simple read-only list tool, the definition covers scope, ordering, and auth, which is most of what an agent needs. It omits any hint about result size or pagination, though with no output schema that is a minor gap rather than a blocker.

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% and the single `list` parameter is already documented as 'Only this shortlist. Optional.' The description's 'only the one named' restates that rather than adding format or matching semantics, so baseline 3 applies.

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 listings in the person's shortlists) and its ordering (newest first), which distinguishes it from write-oriented siblings like save_listing or remove_saved_listing. It doesn't explicitly contrast with search_listings, but the 'shortlists' scope is clear enough to select correctly.

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?

'every list, or only the one named' implies when to supply the optional `list` parameter, so usage is inferable rather than explicit. There is no statement of when-not to use it or which sibling to prefer for other listing retrieval needs.

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