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

With no annotations, the description carries the full burden and does most of it: it discloses pagination semantics ("one page"), the condition for cursor reuse ("only when hasMore is true"), the returned entity fields, and the empty-account case. It omits auth/rate-limit behavior, which keeps it short of a 5.

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?

Five tight sentences, zero filler, front-loaded with the purpose and scoping before behavioral caveats. Every clause adds either disambiguation, return shape, or pagination guidance.

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 3-param list tool with no output schema, the description covers return fields, pagination, empty results, and the downstream handoff. The only gap is operational context such as auth or rate limits, which is minor here.

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 coverage is 100% so the baseline is 3, but the description adds meaning beyond the schema: it ties mixId output to playlist_id input and constrains cursor reuse to hasMore=true, which the schema does not state. That extra semantic layer lifts it above baseline.

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 with explicit scope: "List one page of a creator's public playlists." The phrase "No creator lookup or playlist expansion" and the handoff to playlist_videos clearly separate it from siblings like creator_posts and playlist_videos.

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?

Provides clear usage context and a concrete next step ("Pass a mixId as playlist_id to playlist_videos") plus an exclusion ("No creator lookup or playlist expansion"). It stops short of naming a competing alternative with an explicit when-to-use rule, so it is context-rich but not fully routed.

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