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

Annotations already mark the operation as read-only, idempotent, and non-destructive, and the description adds substantial behavioral detail: results are literal passages, never generated answers; no match returns an empty list; the search is lexical (BM25 over Portuguese stems); and passage text is explicitly framed as data, not instructions. This last point is a valuable security-oriented behavioral disclosure.

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 information-dense and front-loaded with the primary purpose. While it is a long, single-paragraph run-on in places, every clause contributes either behavioral, error-handling, or security-relevant detail, and there is no filler or tautology.

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 search tool with rich annotations, a 100%-described schema, and an output schema, the description covers the core purpose, result semantics, matching algorithm, error conditions, coverage behavior, and a prompt-injection caution. An agent has everything needed to invoke and interpret 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 100%, so the input schema already documents query, slug, and limit. The description mostly restates these semantics (e.g., 'natural-language question or keywords', 'accents are optional; stems are matched') rather than adding new parameter meaning, so the baseline of 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 opens with a specific verb and resource: 'Use to find where the courses talk about something before reading whole modules.' It clearly defines the tool as a cross-course/module passage search and distinguishes it from content-retrieval siblings like getModuleContent by emphasizing search-before-reading. The detailed return-value list further pins down exactly what the tool produces.

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?

It states the intended use case ('before reading whole modules') and clarifies that only courses with retrievable text are searched, with explicit error behaviors for unavailable text and unknown slugs. It does not name sibling tools as alternatives or provide explicit when-not-to-use conditions, but the context is clear enough for an agent to select it appropriately.

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