Get stats for a year

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

The annotation already declares readOnlyHint=true, and the description adds value by specifying that the stats are 'year in review' for the current user, covering specific categories. It does not mention any restrictions (e.g., data availability, rate limits) but is consistent with the safety profile.

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 a single sentence that immediately conveys the tool's purpose and output. Every word is necessary, no redundancy, and the structure is front-loaded with essential information.

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?

Given no output schema and low complexity, the description adequately covers what the tool returns (books finished, time listened, top authors/genres) and that it's user-scoped. It lacks explicit mention of aggregation format or historical depth, but for a simple stats endpoint this is mostly sufficient.

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% with the 'year' parameter fully defined (type, min, max, example). The description adds no additional semantic detail about the parameter beyond restating 'one calendar year', so it does not improve on the schema's existing clarity.

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 clearly states the verb ('Get') and resource ('year in review statistics for the current user'), specifies the content (books finished, time listened, top authors and genres), and distinguishes from sibling tools like get_listening_stats and get_library_stats by focusing on a single calendar year and user-specific review stats.

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 implies use for obtaining annual stats but provides no explicit guidance on when to choose this tool over similar siblings (e.g., get_listening_stats for broader listening stats). No 'when not to use' or alternative suggestions are given, leaving the agent to infer context from the description alone.

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