get_book_excerpt

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

Annotations already mark this as read-only and non-destructive. The description adds behavioral context by specifying exactly what is returned—publisher description, snippet, preview link—and the limitation that it is not full text. This goes beyond the annotations and helps set expectations for the API's constraints.

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 very concise—two sentences—and the first sentence immediately states the tool's purpose. The second sentence adds valuable behavioral limitation without redundancy. Every word earns its place.

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 the tool's simplicity (one parameter) and the presence of an output schema, this description fully covers what the tool does, what it returns, and its key limitation. It also aligns with the read-only annotation. No important contextual element appears 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 single parameter 'isbn' is fully described in the schema as 'ISBN-10 or ISBN-13,' so the description doesn't need to repeat that. The description provides no additional parameter semantics beyond what the schema already states, so a baseline score of 3 is appropriate.

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 begins with 'Get a book excerpt and preview info from Google Books,' which clearly identifies the action and resource. It further specifies the contents of the return: publisher description, text snippet, and link. This distinguishes it from sibling tools like get_book and search_books.

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 explains that Google Books does not expose full chapter text via API, clarifying that this tool only provides excerpts and not full content. It does not explicitly name alternative tools or when to use them, but the context of what this tool returns versus what it cannot provide is clear. Thus it offers clear context without explicit exclusions.

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