hello :) you could imagine the Dataverse MCP connector as a "query generator".
By it self it try to use the tool MCP "describe table" to get table name and then it try to create a query by deducing wich column and table are the good one.
But, in the overview pannel, in instruction part, if you teach the agent the table(s) name(s) you need, and better explain the column and what they contain the agent will then generate accurate query to look for data :)
you just have to use the internal schema name of object in lower case (with this concept you could even describe "linked" table for helping the agent to generate complxe query requiring many table)
if you don't know how to look for table name and schema :
from copilot studio it could be tricky, there is an "easy path" from power apps
check if you are still in you'r environnement, some time it switch when loading :
Then clic on table
and get the name from you table, the technical one in lower case
it will be something probably like gr42_mytablename (custom table have a prefixe "gr42" is just a sample)
the same for column just clic edit column from the table to get the detail
and then you use it inside you'r internal prompt
hope this help :) if it answer or help please check the answer as answered with this post, it's important for the community and search engine :)