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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful behavioral context by specifying the breadth of the search and that results include page URLs, going beyond merely repeating the annotations.

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 concise sentences with no filler: scope, output, and usage condition. The most important identifying information is front-loaded, and the alternative-tool routing appears at the end without bloating the description.

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 read-only search tool with strong annotations and clear schema coverage, the description is complete for selection and invocation. It tells the agent what the search covers, what output to expect (best results with URL), and when to prefer it over sibling tools.

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 67%, covering query and locale. The description adds meaning by clarifying what kinds of terms are valid to search for (Odus, Orixás, Estudos, blog posts, glossary), which goes beyond the schema's generic 'Termo de busca' wording. The limit parameter is not elaborated, but its schema constraints are sufficient.

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 uses a specific verb ('Busca por termo') and names the resource ('toda a biblioteca') while enumerating exactly which content types are searched. It also distinguishes itself from get_* tools by stating it returns best results with page URLs and is meant for unknown slugs.

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 explicitly instructs when to use the tool: 'Use antes de get_odu / get_orixa / get_article quando não souber o slug.' This names the alternative tools and the precise condition that selects search_library over them.

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