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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real behavioral value by disclosing the no-match fallback (returns the full topic list), which the annotations cannot express. It stops short of explaining matching semantics (exact vs fuzzy, case handling).

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 tight sentences, front-loaded with the core action and followed by the return shape and the fallback. No filler or repetition of the name/title.

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 a single well-documented parameter, no output schema and no nested structures, the description supplies everything needed: how matching works, what comes back (topics, books, guide, series), and what happens on no match.

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% and there is a single parameter, so the baseline is 3. The description goes beyond the schema by giving concrete example topic phrases (agent reliability, prompt injection, durable execution), which clarifies the expected granularity of the 'topic' string.

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 (match) and resource (topic/question area against the catalog's curated topic map), and distinguishes itself from generic siblings like search and search_greenlit_books by naming the curated topic map as the mechanism.

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?

Implies the use case (looking up books by topic) and describes the empty-result fallback, but never names an explicit alternative such as search or search_greenlit_books or states when this tool is preferred over them. Adequate but leaves routing to inference.

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