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

The description goes well beyond the annotations by explaining that insights may be generated on demand using the reader's past year of finished books, sent to an AI provider, stored for seven days in place of earlier insights, and counted against AI usage. It also warns that generation takes several seconds and occurs at most once per day, which aligns with the destructiveHint=true and readOnlyHint=false annotations.

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 purpose is front-loaded, followed by operational context and a clear alternative route. The extra detail about generation cost and frequency is valuable rather than redundant, and no sentence is wasted.

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?

The description covers purpose, usage conditions, generation behavior, side effects, cost, cadence, and the best sibling alternative. With an output schema present, it does not need to describe return values, and the annotations are reinforced rather than repeated.

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 tool has zero input parameters and an empty schema, so there are no parameter semantics to clarify. The description appropriately focuses on behavior rather than input details.

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 and resource: it returns written insights about how the reader's reading has been changing across genres, authors, pace, and themes. It also distinguishes itself from the closest sibling by saying that numeric pace and genre data belong to get_reading_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?

It explicitly says when to use the tool: when the reader asks about reading patterns, trends, or trajectory. It also names the alternative for numeric data, get_reading_stats, giving a clear routing rule.

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