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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds meaningful context annotations do not carry: 'Credential-free official Discogs database data' discloses the auth requirement, and the parenthetical enumerates the returned payload domains (artists, tracklist, genres/styles, videos, images, marketplace stats).

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?

Front-loaded with the purpose, then scope, then routing, then param — a sensible ordering with no filler. It loses a point only for restating the id definition already present in the schema.

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 not be explained, yet the description still summarizes the payload domains. Combined with the credential note and the sibling routing, the definition is complete for a single-parameter lookup tool.

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% and the schema already documents 'id' with the same example (26647), which the description repeats verbatim. No additional syntax or format guidance is offered, so the baseline 3 applies.

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 ('Returns') and resource ('Discogs master release'), then defines the concept as the version-agnostic grouping across pressings/reissues. It explicitly names the sibling distinction, so an agent can tell it apart from discogs_release without opening either schema.

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 final sentence routes the agent: 'Use discogs_release to get a Discogs release,' which names the alternative tool. The scope-defining clause ('version-agnostic grouping across pressings/reissues') implies when a master is preferable, but it never states an explicit preference rule such as browsing a discography vs. a specific pressing.

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