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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety/scope profile is covered. The description usefully adds the credit cost, which is not in the schema or annotations, but says nothing about result freshness, pagination, or how cache_max_age affects behavior.

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 short sentences, front-loaded with the resource and followed by the credit cost. The leading 'Charts.' echoes the title and could be dropped, but the rest is efficient and free of filler.

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 and three undocumented parameters, the description should do more, particularly for cache_max_age and for what a chart entry contains (rank, position, streaming data?). It is adequate to identify the tool but leaves gaps an agent needs when constructing a call.

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 0%, so the description must carry parameter meaning, and it does not: it repeats the enum values for 'type' (which the enum already conveys) and says nothing about 'limit' or the opaque 'cache_max_age' string parameter. An agent has no way to know what cache_max_age accepts or how limit interacts with charts.

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 the resource (Deezer charts) and enumerates the entity kinds covered (tracks, albums, artists, playlists, podcasts), which is a concrete verb+resource statement. It does not explicitly distinguish itself from siblings like deezer_search or deezer_artistTopTracks, so the agent must infer that this returns global charts rather than per-artist or keyword-based results.

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?

Usage is implied by the word 'global top' charts, but there is no explicit when-to-use guidance and no mention of when to prefer deezer_search or deezer_artistTopTracks instead. The 'Costs 1 credit' note gives a cost signal but is not usage guidance.

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