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

The readOnlyHint annotation already covers the safety profile, and the description adds that this returns a catalog of the entire library. However, it does not disclose response shape, pagination, ordering, or any other behavioral details beyond being a read-only listing.

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?

Two short sentences carry the full meaning: the first defines what the tool returns, and the second gives the intended use. There is no filler or redundant restating of the title.

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 zero-parameter read-only listing tool, the description is nearly complete: it conveys scope, contents, and when to use it. The only gap is the absence of an output schema or any statement about the exact response structure, but that is a minor concern for such a simple tool.

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 parameters and the schema covers 100% of them, so the baseline is 4. The description reinforces that the tool returns the full catalog by saying 'every book and collection,' which adds mild extra meaning over the empty schema.

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 ('every book and collection on TheWholeTorah.ai') and the included details ('sections and published lesson counts'). It also distinguishes the tool from search tools by positioning it as a catalog to consult before searching.

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 explicitly says to use it 'to see what the library covers before searching,' which gives clear context for when to call it. It does not explicitly name alternatives like search_lessons or search_sources, but the 'before searching' phrase implies the boundary.

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