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

Annotations already declare readOnly=true, idempotent=true, openWorld=false, destructive=false, so the safety profile is covered. The description adds genuine context beyond that: the exact corpus indexed, return ordering (best first), the returned artifacts (url to quote, page to read for more), the empty-result case, and the explicit non-searchable remainder of each book.

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?

Front-loaded with the core purpose and one dense but purposeful second sentence covering scope and return shape; the caveats about empty results and non-searchable content are appended efficiently. The middle corpus enumeration is long but each item earns its place by defining coverage boundaries.

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 does the work of describing the return: ranked passages with a url and a page reference. Combined with the empty-result and scope caveats, an agent has enough to call and interpret this tool; only the interaction with alternative lookup tools is unaddressed.

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 book, limit (with min/max and default) and question are already documented in the schema, including a worked example for question. The description adds no syntax, slug format, or limit guidance beyond what the schema already provides, so the baseline 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?

States a specific verb (find) and resource (what the Greenlit books say), and enumerates exactly which corpora are searched (free chapter one, named concept, FAQ, glossary, claim ledger, guides) plus the two retrieval modes (words and meaning). An agent can distinguish this from siblings like search_greenlit_books or get_concept without opening a schema.

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?

Gives a clear trigger condition: 'Use it when a user asks how, why or what about building, running, securing or trusting AI agents, or about an idea or term from these books.' It also states a negative behavior ('returns nothing when no passage bears on the question') and a scope boundary ('the rest of each book is not searchable here'). No sibling is named as an alternative, so the routing to check_claim, define_term or cite_source is left to inference.

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