Precomputed listening stats

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond them: the data is precomputed and refreshed only every few hours (staleness) and 'eras' depends on how the warehouse is configured, which an agent cannot learn from the schema.

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 core statement (all-time aggregates, refresh cadence), then a tight value-by-value enumeration with no filler or repetition. Dense but every clause carries information; only minor loss for the run-on final sentence.

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?

With no output schema, the description must convey what comes back, and defining each stat category does that at a conceptual level. It stops short of describing response shape, grouping, or pagination, but for a read-only aggregate tool with one enum input this is nearly complete.

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 0% and the single enum parameter's five values are otherwise opaque strings, yet the description defines each one concretely (on-repeat = last-14-day over-play, rhythm = streaks/hourly, top-over-time = per quarter/year, eras = taste shift, albums = all-time/yearly). This is the parameter's documentation in all but schema form.

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 states a specific resource ('all-time aggregates' plus five named stat categories), so an agent knows this returns precomputed listening statistics. It does not, however, explicitly distinguish itself from siblings like top_artists, top_tracks, or daily_play_counts, which overlap in subject matter, so sibling differentiation is left to inference.

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 context is implied rather than stated: 'refreshed every few hours' signals this is a cached/aggregate read, contrasting with live siblings like recently_played_live or now_playing, but the description never says when to prefer this over top_artists/top_tracks. No explicit exclusions or alternative routing.

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