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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, and the description does not contradict them. It adds useful context beyond the annotations: the search is limited to an 'indexed corpus of top public-domain books,' and the response will include matched passages with title, author, and snippet. This is sufficient for a read-only search tool.

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?

Three focused sentences with no wasted words. The key action ('Search INSIDE') is front-loaded, and the return content plus optional restriction are stated compactly. Every sentence 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?

With no output schema, the description compensates by specifying exactly what the agent can expect back: matching passages with book title, author, and snippet. It also covers the optional gutenberg_id restriction, and the limit parameter is documented in the schema. For a low-complexity, read-only search tool, nothing essential is 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?

Schema description coverage is 100%, so the schema already documents all three parameters: query, limit, and gutenberg_id. The description only restates the gutenberg_id restriction and does not add new semantic detail beyond what the schema provides. Baseline 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 clearly identifies a specific verb ('Search INSIDE'), a resource ('the indexed corpus of top public-domain books'), and the result shape ('matching passages, each with the book title, author, and a snippet'). It also distinguishes itself from sibling tools like book_search by emphasizing full-text passage retrieval rather than metadata search.

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 clear context: it is for finding passages within the full text of public-domain books, with an optional restriction by gutenberg_id. It does not explicitly state when to prefer it over siblings like book_search or book_get_text, but the phrase 'headline feature' and the focus on inside-text search make the intended use case clear.

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