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

Annotations already declare read-only, idempotent and closed-world behavior, so the safety profile is covered. The description adds real behavioral detail beyond that: results are ordered best first, each carries id/title/url, and an empty result set means Bettyapp has no lecture on the topic. It leaves out how many results come back and whether the query can be empty-ish, but the added context is substantive.

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?

Four short sentences, front-loaded with what the tool does, then return shape, then the alternative, then the empty-result semantics. Every sentence carries information an agent needs and nothing is repeated from the schema or annotations.

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 an output schema present and annotations covering the safety profile, the description doesn't need to explain return values, and it still covers ordering, the empty case, and the richer sibling. The only minor gap is not clarifying what happens with an empty or one-character query.

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 the schema itself already tells the agent the query should be one to four words phrased as a teacher would say it. The description's phrasing ('a topic or question') adds only marginal meaning beyond that, 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 (search), a specific resource corpus (Bettyapp's university and school lectures) and the unit returned (moments that explain a topic or question). It also distinguishes itself from siblings by saying each result carries an id for fetch and that search_moments returns a richer record.

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?

Explicitly routes the agent to search_moments when the caller needs the summary, teacher and credit line, which is a clear when-to-use-alternative condition. It doesn't address the other siblings (get_topic, list_subjects, get_lecture) or state any exclusions, so it falls just short of full routing guidance.

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