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

Annotations already mark the tool as read-only, open-world, idempotent, and non-destructive. The description adds useful behavioral detail beyond those annotations: the no-path default behavior and the shape of the result ('description, subcategories and books'). The only omission is error behavior for invalid paths, which is minor for a read-only browse operation.

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 compact and front-loaded, with two sentences that each carry distinct information. Listing the top-level categories and giving concrete path examples makes it immediately usable without unnecessary prose.

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 one-optional-parameter, read-only browse tool without an output schema, the description gives enough information: the default behavior, the path behavior, and the response content. No critical calling detail is missing.

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 schema already documents category_path as a string with an example, and description coverage is 100%. The description adds meaningful semantic value by explaining that the parameter is optional and by illustrating deeper paths like 'Talmud/Bavli/Seder Moed' and 'Halakhah/Shulchan Arukh', which clarifies the hierarchy format.

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 action ('Browse the library's table of contents by category') and exactly what is returned for both no-path and path calls. It distinguishes browsing a hierarchical catalog from other library tools like search_library or get_book_info.

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 gives clear context for when to use the tool: 'With no path' returns top-level categories, and 'With a path like...' returns category details. It does not explicitly name alternatives or exclusions, but the branch-based usage is easy for an agent to act on.

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