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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is well covered. The description adds that this returns a table of contents and supports group filtering, but does not disclose ordering, pagination, or response shape beyond that.

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 efficient sentence that front-loads the core purpose and then supplies the optional filter values. There is no redundant or filler text.

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 read-only list operation with one optional parameter and no output schema, the description provides enough context to call the tool correctly, including the filter values. Minor omissions such as ordering or pagination are unlikely to prevent correct invocation.

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 0%, and the schema only defines a generic string for group without allowed values. The description compensates substantially by listing the valid group values: front-matter, essays, editions, collectors, dao, conclusion, and reference. It still lacks details such as case sensitivity, exact-match behavior, or default when omitted.

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 identifies the resource as the table of contents of XCOPYBook and indicates it can be filtered by group. It is distinguishable from get_chapter, which retrieves a single chapter, though sibling differentiation is implicit rather than explicit.

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 phrase 'optionally filtered by group' implies the primary usage context, and the listed group values clarify what filtering is possible. However, it does not explicitly state when to use this tool versus alternatives like get_chapter or search_book.

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