Add richer OTel MCP span attributes #1753

Job	Run time
checks / pre-commit	32s
checks / readme-snippets	11s
checks / test (3.10, locked, ubuntu-latest)	50s
checks / test (3.10, locked, windows-latest)	2m 30s
checks / test (3.11, lowest-direct, windows-latest)	2m 50s
checks / test (3.13, locked, windows-latest)	2m 26s
checks / test (3.11, locked, ubuntu-latest)	54s
checks / test (3.12, lowest-direct, windows-latest)	3m 49s
checks / test (3.13, locked, ubuntu-latest)	48s
checks / test (3.11, lowest-direct, ubuntu-latest)	57s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 0s
checks / test (3.13, lowest-direct, ubuntu-latest)	50s
checks / test (3.10, lowest-direct, ubuntu-latest)	56s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 20s
checks / test (3.11, locked, windows-latest)	2m 43s
checks / test (3.12, locked, windows-latest)	3m 11s
checks / test (3.10, lowest-direct, windows-latest)	2m 42s
checks / test (3.12, locked, ubuntu-latest)	56s
checks / test (3.14, lowest-direct, windows-latest)	2m 25s
checks / test (3.14, locked, windows-latest)	3m 28s
checks / test (3.13, lowest-direct, windows-latest)	2m 52s
checks / test (3.14, locked, ubuntu-latest)	2m 20s
all-green	3s
	40m 33s

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