
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given the function $f(x)=2\cos \left( \frac {\pi}{2}-x\right)\cos \left(x+ \frac {\pi}{3}\right)+ \frac { \sqrt {3}}{2}$.
- (I) Find the smallest positive period and the intervals of monotonic decrease for the function $f(x)$;
- (II) Find the range of $f(x)$ in the interval $\left[0, \frac {\pi}{2}\right]$.

Present the answer in LaTex format: \boxed{Your answer}
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