Modelling for similarity between two descriptions
So the questions asks for how to compute similarity between the organisation description and project titles.
One initial thought would be to use a Doc2Vec model (concept, implementation), which will take the organisation descriptions and project titles as input and output a n-dimensional vector in semantic space for the given text.
From this, you can at least has a baseline which you can use with cosine similarity to see how similar the organisation description is to the project title.