weekday_heatmap

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

No annotations are provided, so the description carries the burden. It discloses quota ('🟢 1-2 reads, local compute'), which is helpful behavioral context. However, it doesn't state whether it requires recently-played history, whether pagination pages are walked from the start, or whether the heatmap is returned as structured data vs prose. It's a read-only tool by nature but that's not explicit.

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 with zero waste: the first explains what the tool does and how it relates to a sibling; the second communicates quota and compute cost. Front-loaded with the core behavior.

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 read-only aggregation tool with two well-documented parameters and no output schema, the description is mostly complete. It explains the bucketing, the distinction from the hour-of-day heatmap, and quota. Minor gaps: doesn't say what data source is used (recently played vs full history) or whether 'pages' implies walking recently-played pages in order.

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% — both pages and response_format have descriptions in the schema. The tool description adds no additional parameter semantics beyond stating the daypart buckets. Baseline 3 is appropriate because the schema already documents the parameters.

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?

Description clearly states the tool groups plays by weekday and daypart (morning/afternoon/evening/night), and differentiates it from listening_heatmap which is hour-of-day. This distinguishes it from sibling tools like listening_clock_heatmap and weekday_listening_report.

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 says 'listening_heatmap is hour-of-day; this adds the weekly dimension', which tells the agent when to choose this tool over the most similar alternative. It doesn't enumerate all possible alternatives or exclusions, but the context is clear.

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