fix: correct unknown tool/prompt/resource error handling #713

Job	Run time
checks / pre-commit	32s
checks / readme-snippets	14s
checks / test (3.11, lowest-direct, ubuntu-latest)	55s
checks / test (3.10, locked, windows-latest)	2m 52s
checks / test (3.11, locked, ubuntu-latest)	50s
checks / test (3.10, locked, ubuntu-latest)	53s
checks / test (3.11, locked, windows-latest)	2m 33s
checks / test (3.11, lowest-direct, windows-latest)	2m 37s
checks / test (3.10, lowest-direct, ubuntu-latest)	57s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 0s
checks / test (3.14, locked, ubuntu-latest)	2m 19s
checks / test (3.10, lowest-direct, windows-latest)	2m 25s
checks / test (3.12, locked, ubuntu-latest)	54s
checks / test (3.14, locked, windows-latest)	3m 21s
checks / test (3.13, locked, ubuntu-latest)	46s
checks / test (3.13, lowest-direct, windows-latest)	2m 33s
checks / test (3.12, locked, windows-latest)	3m 15s
checks / test (3.13, locked, windows-latest)	2m 28s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 19s
checks / test (3.13, lowest-direct, ubuntu-latest)	56s
checks / test (3.14, lowest-direct, windows-latest)	2m 43s
checks / test (3.12, lowest-direct, windows-latest)	3m 36s
all-green	4s
	40m 2s

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