get_reader_bookmark

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

With no annotations, the description must carry the behavioral load. It discloses that the data is local and independent from WeChat Reading progress, and that the no-parameter call returns all titles. It does not explicitly state read-only/no side effects, permissions, or error behavior, but the 'get/return' language strongly implies a query operation. This adds meaningful context but leaves the safety profile implicit.

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?

One compact sentence, front-loaded with purpose and scope, then the invocation note. Every clause earns its place; no filler or repetition.

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?

The output schema exists, so return-value documentation is already available. The description covers the primary no-parameter call path and the local nature of the data. The main gap is the effect of book_id and the relationship to sibling tools, which an agent would need to infer. For a low-complexity tool with one optional param, this is adequate but not comprehensive.

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 0%, so the description must compensate. It clarifies that omitting book_id returns all books, which is the key semantic for the only parameter. However, it does not explain what happens when book_id is supplied (e.g., filtering to one book), so compensation is partial.

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 as the AI reading companion's local progress and explicitly distinguishes it from WeChat Reading's real progress. It also states that calling without parameters returns the full book list. However, it does not directly name sibling tools like get_progress or set_reader_bookmark to differentiate from them, so it stops short of full sibling-level clarity.

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 provides an explicit invocation hint ('不带参返回全部书目' – return the full list without parameters) and contextualizes the tool as local-only, which helps an agent decide when this tool fits. But it offers no explicit when-to-use vs alternatives or any exclusion criteria, leaving comparison with get_progress/get_shelf to inference.

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