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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds two genuinely useful behavioral facts not in structured data: only public playlists are readable, and each call 'Costs 1 credit' (a rate/cost constraint). It does not mention pagination termination or what a truncated track list looks like, so it adds value but not rich context.

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?

Three short sentences, front-loaded with the resource and the returned fields, with the paging hint and cost note trailing. The opening fragment 'Playlist contents.' duplicates the title slightly, but nothing is padded.

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?

With no output schema, the description correctly fills that gap by enumerating the returned fields, and it explains pagination via `cursor`. What remains thin is routing guidance versus sibling playlist tools and any mention of `cache_max_age`, but for a one-required-param read tool it is close to complete.

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 67%; `id` and `cursor` are documented in the schema and the description reinforces cursor usage by tying it to paging long track lists. The third parameter, `cache_max_age`, is undocumented in both the schema and the description, which is a small but real gap. Baseline 3 fits given the schema does most of the work.

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 concrete resource and enumerates exactly what is returned (title, owner, description, cover, track count, fans, tracks), so an agent knows this is a playlist-detail fetch rather than a search. It stops short of naming how it differs from sibling deezer_userPlaylists or deezer_search, which is the only thing separating it from a 5.

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 only usage signal is 'Pass `cursor` to page the tracks of a long playlist,' which is a pagination hint rather than a when-to-use rule. Nothing tells the agent when to choose this over deezer_userPlaylists (listing a user's playlists) or deezer_search (finding a playlist by name), so selection must be inferred.

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