artist_history

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and idempotentHint=true, indicating safe, non-destructive, and idempotent behavior. The description adds that the result is 'approximate' (not exact) and that a local default for username may exist, which are useful context not captured by annotations or schema. No contradiction.

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 sentences, no filler. The main action and return value are front-loaded, and the username note is brief. Only minor improvement would be to explicitly state the tool name in the description for clarity.

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 simple read-only check with two parameters fully described in schema, the description covers the primary purpose and the only subtlety (username default). It does not specify what happens when the user has never listened (e.g., returns zero scrobbles or an error), but given no output schema and low complexity, this is a minor gap.

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 the schema already documents both parameters. The description clarifies that username is optional only under a specific server condition, which adds a little beyond the schema. 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 specific verb ('Check whether'), resource ('whether a Last.fm user has listened to an artist'), and the return value ('approximate total scrobble count'). It directly distinguishes from siblings like top_items or recent_scrobbles by focusing on a single artist check rather than lists.

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?

Provides the core use case (checking if a user has listened to an artist) and notes that a username must be passed unless the server has a local default. However, it does not explicitly contrast with sibling tools (e.g., when to use recent_scrobbles instead), and gives no guidance on when not to use this tool.

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