itunes_get_monthly_replay

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

No annotations are provided, so the description carries the full burden. It discloses the output format (a formatted summary listing listening time, play count, etc.) and implies a read-only computation ('Generate'), but it does not explicitly state that no data is modified or that no special permissions are required. For a report tool, this is adequate but not fully 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?

The description is efficiently structured with a clear purpose statement, an Args block that adds meaning beyond schema, and a Returns block that lists expected output fields. Every sentence adds value without fluff or redundancy.

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 2-parameter tool with no output schema, the description fully explains the return format. It does not mention edge cases like 'no listening data available', but such omissions are minor given the low tool complexity and the clarity of the report output.

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 provides only property titles and defaults, with no descriptions. The description adds crucial meaning: year/month values, valid ranges (1-12 for month), and that 0 means 'use current'. This compensates well for the low schema coverage.

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 verb 'Generate' with a specific resource ('Apple Music Replay listening report') and scope ('for a specific month and year'). This clearly differentiates the tool from siblings like itunes_get_stats or itunes_get_listening_history, which serve different reporting purposes.

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 conveys clear usage context: it generates a monthly/yearly replay report when the user wants listening summary data for a specific period. It does not explicitly mention alternatives or when-not-to-use, but the scope is well-defined, so the usage intent is clear.

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