Get reading progress

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

With no annotations, the description carries the burden. It discloses the return contents (per-file percentage, position, optional audiobook progress) and the conditional 'when present' behavior. However, it does not mention what happens when there is no progress, potential auth requirements, or explicitly confirm there are no side effects.

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 tight sentences: the first states the core behavior and output, the second gives a concrete use case. No extraneous words.

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 single-parameter read-only getter, the description covers purpose, input, output shape, and a retrieval use case. It omits edge-case behavior like missing progress, but that is not critical for this 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?

Schema coverage is 100%, including a clear description of bookId as coming from search_books. The description mentions 'by bookId' but adds no additional semantic detail, so the baseline of 3 applies.

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 uses a specific verb ('Get') and resource ('reading progress for one book'), names the lookup key (bookId), and summarizes the output fields. This clearly distinguishes it from sibling tools like get_reading_stats or get_reading_sessions, which address different questions.

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?

It gives an explicit use case: answer 'where am I in this book'. This is clear context, but it does not provide when-not-to-use guidance or name alternatives like get_reading_sessions for broader session history.

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