Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It reveals the report is 'deep, cited' and includes a concrete data point, which is useful. But it does not disclose how the tool behaves: whether it performs live web research, synthesizes from a fixed knowledge base, how citations are formatted, whether output is a markdown document, or any limitations. The 'input=optional scope' hint is ambiguous about what happens when input is omitted.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.