* fix(reporting): restore create_vulnerability_report parameter descriptions
A docstring line beginning with a backtick fence example opened a markdown
code block that griffe's Google-style parser never saw closed, so the Args
section was parsed as plain text and the generated tool schema carried no
per-parameter descriptions. Reword the example, move Args after the trailing
notes so nothing after it is dropped from the tool description, and add a
test asserting every scan-agent tool parameter has a description.
* test(reporting): cover respond_to_user and reject null parameter descriptions
