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

Annotations already declare readOnlyHint and openWorldHint, but the description adds useful behavioral context: tracks and albums are returned as posts, artists as creators, and each call costs 1 credit. It does not contradict the annotations.

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?

The description is short and front-loaded with purpose and return-shape information. The opening "Search." is redundant with the title, but the remaining sentences are efficient.

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 search tool with no output schema, the description adequately covers purpose, return shape, and cost. It leaves some schema-level details like limit and caching to the input schema, which is reasonable given annotation coverage.

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 60%, so some parameter meaning is already documented. The description mentions track/album/artist categories matching the type enum, but adds no detail on query, limit, country, or cache_max_age beyond the schema.

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 gives a specific verb and resource: "Search the Apple Music catalogue for tracks, albums or artists." It is clear what the tool does, though it does not explicitly differentiate itself from sibling tools like appleMusic_track or appleMusic_artist.

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 implies usage by saying it searches the catalogue for tracks, albums, or artists, but it gives no explicit when-to-use guidance or alternatives. It does not mention when to use appleMusic_album, appleMusic_artist, or appleMusic_track instead.

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