whoami

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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds value by disclosing the shape of the payload (profile plus collection and wantlist counts) in the absence of an output schema, but it stops short of describing what 'profile' contains or how counts are scoped.

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?

A single front-loaded sentence with no filler; every clause (identity, profile, sizes) carries information about the response.

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 zero-parameter read with annotations covering safety and no output schema, the description does enough by previewing the returned fields. It is slightly thin on what 'profile' and the size values actually contain.

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?

The tool takes zero parameters, so the baseline of 4 applies; there is no parameter meaning for the description to supply.

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 names a specific resource (the authenticated Discogs user) and enumerates what it returns (username, profile, collection/wantlist sizes), so an agent can tell it apart from the many collection-mutating siblings at a glance. It lacks an explicit verb like 'get', but the intent is unambiguous.

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 only implied: an agent can infer this identifies the current user before calling user-scoped tools, but the description names no when-to-use condition and no alternative. There is no obvious sibling that does the same thing, so the omission costs little.

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