book_open

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

With no annotations, the description carries the full behavioral burden, yet it discloses nothing beyond the verb: not whether opening loads the book into the Books panel, whether it is idempotent if the book is already open, what permissions or path constraints apply, or whether it mutates application state. For a state-changing open operation this is a significant gap.

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?

A single short sentence with no wasted words and the resource front-loaded. It is efficient, though the terseness is part of what leaves the behavioral and parameter gaps.

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 state-changing tool with no annotations, no output schema, and one undocumented required parameter, the description is not complete enough for an agent to call it correctly in ambiguous cases (e.g., relative paths, already-open books). It needs at least a path expectation and a note on post-open state.

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 description coverage is only 50%: document_id is documented in the schema, but filePath has no description at all (only a type and minLength), and the description adds no path format, absolute-vs-relative, or extension requirements. With coverage this low, the description needed to compensate and does not.

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 gives a specific verb ("Open") and resource ("InDesign book file (.indb)"), and the .indb qualifier implicitly separates it from document_open, which handles .indd documents. It stops short of naming that sibling or stating scope explicitly, so it is clear but not fully differentiated.

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?

No guidance on when to use this versus document_open, book_list, or book_getDocuments, and no prerequisites such as whether the file must exist on disk or whether the book must already be registered. The agent is left to infer usage entirely from the file extension.

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