user_get_loved_tracks

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

readOnlyHint=true already tells the agent this is a safe read, so the description's main contribution is ordering ('newest first') and the fact that a loved-date field comes back — both genuinely useful and not in any annotation. It does not mention anything about the configured-user default, empty results, or paging behavior beyond what the schema states.

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?

One tight sentence with the resource and sort order front-loaded and no filler. The only flaw is the missing verb ('Tracks the user marked...' reads as a fragment), which briefly delays parsing.

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 three-parameter read tool with fully documented schema and a readOnly annotation, this covers the essentials: what is returned, in what order, and with what extra field. No output schema exists, and the description adequately characterizes the return shape; only the alternative-selection guidance is missing.

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 coverage is 100% — page, user (including the LASTFM_USERNAME default) and limit are all documented in the schema itself. The description adds no additional parameter meaning, 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?

The description identifies a specific resource — tracks the user marked as loved (hearted) on Last.fm — and the parenthetical '(hearted)' pins down the exact Last.fm concept, which separates it from siblings like user_get_recent_tracks or user_get_top_tracks. It is a noun phrase rather than a verb phrase ('Retrieve...'), so the action must be inferred, and no sibling is named 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?

There is no when-to-use or when-not-to-use guidance. With 23 siblings including three other user track-listing tools, the description never says 'use this instead of user_get_recent_tracks when you want explicitly hearted tracks' or notes any precondition. The agent must derive selection criteria from the word 'loved' alone.

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