search_in_book

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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals that matching is substring-based, works for both Chinese and English without word segmentation, queries a local text index, and returns snippets for quoting. This is meaningful context beyond the schema, though it does not state whether the operation is read-only or describe error behavior.

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 tightly structured: a purpose line, prerequisite and matching semantics, then a clean Args list. Every sentence adds distinct value and there is no filler or restatement of the tool name.

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 3-parameter search tool with an output schema, the description covers prerequisites, search semantics, param semantics, and output behavior (snippets for quoting). The output schema exists, so the description does not need to document return fields. Nothing essential is missing for an agent to invoke this tool correctly.

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 0%, but the description fully compensates by documenting all three parameters: query as the text to find, book_id as an optional single-book restriction, and limit with its range and default. It even adds the 1-100 constraint not present as an explicit schema boundary.

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 opens with a specific verb and resource: "Full-text search inside book contents, with match snippets for quoting." This clearly differentiates the tool from siblings like search_books (metadata search) and read_book (reading content), so an agent can select it correctly without inspecting sibling schemas.

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 gives a clear precondition: "books must be indexed first with build_index (a one-time, cached step)." This tells the agent when the tool is usable and names the prerequisite tool. It does not explicitly contrast with search_books or explain when not to use it, so it stops short of a perfect 5.

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