lastfm_get_user_info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds value by specifying the exact data returned (playcount, registration date, country, profile URL), which provides behavioral clarity beyond 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 concise with two sentences. It front-loads the purpose ('Get profile information for a Last.fm user.') and provides essential details without unnecessary words.

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?

Given the low complexity (one parameter, output schema exists), the description is sufficiently complete. It lists key return fields, and the presence of an output schema (not shown but referenced) means the description does not need to detail the full return structure. Slight improvement could include mention of idempotency or read-only nature, but annotations already cover that.

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 input schema includes a single parameter 'username' with the description 'Last.fm username'. The tool description does not add any additional meaning or guidance beyond what the schema provides. Since schema description coverage is listed as 0% (but actually the parameter has a description), the tool description compensates minimally. A score of 3 reflects that the schema itself handles the parameter documentation sufficiently.

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 clearly states it retrieves profile information for a Last.fm user and lists the specific data fields returned (playcount, registration date, country, profile URL). It is distinct from sibling tools which focus on other entities (albums, artists, tracks) or other user-specific data (loved tracks, top albums).

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 does not explicitly state when to use this tool versus alternatives. While the sibling tools provide implicit context (e.g., use this for general profile info and sibling user tools for specific lists), no explicit when-to-use or when-not-to-use guidance is given.

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