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

The annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds a genuinely useful behavioral detail not present in any structured field — that no Spotify bearer token is required — which changes how an agent would attempt the call.

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 compact sentences, front-loaded with what is returned and the identifier requirement, with no redundant or filler content.

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?

An output schema exists, so return values need no explanation, and annotations cover the safety profile. The added auth note and use-case routing make it nearly complete for a simple read endpoint; only the relationship to sibling artist sub-resources is left implicit.

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%, so both id and uri are fully documented in the schema. The description only restates that a URI or ID is accepted, adding no syntax or precedence detail beyond what the schema provides. Baseline 3 is appropriate.

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 ("Returns Spotify artist overview data") and names the accepted identifier types (URI or ID). It differentiates itself from sibling endpoints like spotify_artist_albums or spotify_artist_related by scoping to the artist overview, though it does not name those siblings explicitly.

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?

"Use when you have an artist URI or ID; search first only if you need to find one" gives clear when-to-use context and routes to the search sibling for the discovery case. It stops short of enumerating other artist sub-resources (albums/playlists/related) that an agent might confuse it with.

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